Green Fertilization

While the decrease in soil fertility has become a critical problem for agricultural production and food security worldwide, on the other hand, the demand for food is increasing due to rapid population growth. In the loss of the fertility power of agricultural soils; A number of known agricultural activities such as growing the same product for years in a row or not showing the necessary sensitivity to crop rotation, applying unconscious fertilization and irrigation programs that are not based on soil and water analysis in order to increase yield and quality, and using herbicides and pesticides play an important role. Green manuring is considered an effective strategy to improve soil quality and health in agroecosystems. In this book, green Fertilization plants and green Fertilization; The role of the physical, chemical and biological properties of soils in improving the yield and quality of agricultural products grown after them, and their importance in the control of weeds, diseases and pests are discussed within the framework of sustainable agricultural approach. We would like to sincerely thank all the authors who contributed to the chapters of our book, and we hope that it will be useful to all stakeholders.

PART 1

GREEN FERTILIZATION AND PLANTS USED FOR GREEN FERTILIZATION

ENTRANCE

Today, in order to meet the food demand of the increasing population; Increasing and developing agricultural production, protecting agricultural systems, reducing the pressure on agricultural areas and eliminating environmental problems are among the most important goals of countries and agricultural organizations.

In agricultural problems; degradation of agricultural soils, soil quality, excessive and unconscious use of chemical fertilizers to increase agricultural production. Problems arising from the use of chemical fertilizers also cause increased greenhouse gas emissions and soil acidity (Hou et al., 2010), degradation of the ecosystem and decrease of biodiversity (Majeed et al., 2015), disruption of soil nutrient balance, and chemical imbalance in the soil (Asghar and Kataoka, 2022). For this reason, it is necessary to disseminate and develop sustainable agricultural techniques in order to reduce agricultural environmental problems, to increase and/or improve the productivity of products and soils.

In this sense, green Fertilization, which is the oldest known practice, is one of the alternative strategies that protect the environment and soil health, increase soil quality and plant productivity.

Green manuring is considered a good agricultural practice to improve the organic matter and fertility of the soil (Balachandar et al., 2020); helps to increase the growth and yield of crops (Yang et al., 2017; Zhou et al., 2020). In this respect, green Fertilization is the most important component of sustainable agricultural systems. In this section, green Fertilization plants, which are the basic elements of green manure, and the importance and benefits of green manure technique are emphasized.

DEFINITION OF GREEN MANURE AND GREEN FERTILIZATION

Green Fertilization, also called productivity-enhancing crops, are broadly defined as crops grown for the benefit of the soil (Knight et al., 2022).

In order to improve the structure of the soil and increase productivity in plant production, green fertilization is defined as the process of mixing leguminous and/or non-leguminous plants into the soil in a green state during a certain period of their development  . Plants grown for green Fertilization are also  called green Fertilization plants. Meena et al. (2020) define green manure; They described it as the process of adding or subsoiling plants in the green stage or flowering phase grown in the field or elsewhere by growing any green plant in the field.

ISSUES TO BE CONSIDERED IN THE SELECTION OF GREEN FERTILIZER PLANTS

The characteristics of the green Fertilization plant and the points to be considered in the selection of the green manure plant are listed below:

1. First of all, the green Fertilization plant to be selected must be suitable for the soil, climate and growing conditions (Aydeniz and Brohi, 1993).
2. Inexpensive seed material,
3. Have the ability to germinate and grow quickly,
4. Easy to plant (Rayns and Rosenfeld, 2010),
5. High competition with weeds,
6. Resistant to pests and diseases (Rayns and Rosenfeld, 2010),
7. It has the ability to grow in infertile soils,
8. Producing abundant vegetative parts,
9. In order to improve the physical, chemical and biological properties of the soil, dry matter production and legumes have a high nitrogen (N) fixation capacity,
10. It requires the least cultural practices to be more economical, k) They are fast growing and high biomass producers with minimum nutrient and water requirements,
11. It should be easy to apply and mix into the soil (Aydeniz and Brohi, 1993),
12. In the soil, it breaks down easily and in a short time; in other words, the selection of species with a low ratio of carbon to nitrogen (C/N) (Ávila-Escobedo et al., 2022),
13. Suitability for animal feed (Rayns and Rosenfeld, 2010),
14. They are especially suitable for short-term crop rotation systems, p) The possibility of weeds for the next crop (Rayns and

Rosenfeld, 2010).

PLANTS USED FOR GREEN FERTILIZATION

In order to improve the physical, chemical and biological structure of the soil and to increase the yield of the products that come after it, the plants that are mixed into the soil in a green state in a certain period of maturity are called green manure plants. A wide variety of plants can be used for green manure. Although the general rules stated under the previous main heading are valid in plant selection; Depending on factors such as climatic conditions, the cultivation system applied, and local habits, the plants used may vary. In general, legume plants are used for green manure purposes because they have biological N fixation capacity. In addition, in green manure, non-leguminous plants are also mixed into the soil as green by growing them both in lean form and with some legumes by mixed planting.

Legumes, which are used as green manure, are generally annual species. However, in some parts of the world, such as in the northern and central regions of the United States (USA), most of the legumes used for this purpose are perennial species (Shrestha et al., 1999). Again, in some countries, certain species have come to the fore for green manure. For example; In countries such as Germany, England, the Netherlands and Denmark, the lupine (Lupinus spp.) plant plays an important role in green manure, especially in sandy soils (Pieters, 1927). The most important legumes used for green manure in the tropics  are Crotalaria juncea, Sesbania aculeata and Dolichos uniflorus (Pieters, 1927).

Major Legume Green Manure Crops

• Alfalfa (Medicago sativa L.)

Alfalfa (Medicago sativa L.) (Figure 1) has high yield potential, wide adaptability and high nutritional value (rich in protein, fiber, vitamins and mineral elements); It is an important perennial, leguminous plant that is most widely used for fodder crop purposes worldwide due to its production of tasty forage (Baslam et al., 2013; Bıçakçı and Balabanlı, 2016; Açıkbaş et al., 2017; Noori et al., 2018).

Figure 1. Common clover (Medicago sativa)

Alfalfa, which can be used in many areas as a forage plant, is also; having a high phosphorus (P) content (0.30-0.42%) and reducing P losses in field soil (Gao et al., 2022), organic acids in green manure reduce the absorption of phosphorus on soil particles, thus enabling phosphorus to be converted into a form that can be taken up by plants in the soil (Azeez and Van Averbeke, 2011), and being able to use deep soil water in the most effective way with its deep (3-5 m) and wide roots (Ghimire et al.,  2014), promoting biological activity in the soil and improving nutrient turnover in the soil (Testa et al., 2011; Gao et al., 2016) is an excellent source of green manure with important features such as producing a large number of upright stems and having quite a lot of above-ground parts due to the fact that these stems are covered with dense short branches and leaves.

Annual clovers (medics) (Medicago spp.)

Some annual medic species, such as Medicago truncatula Gaertn., M. lupulina L., M. polymorpha L. (Figure 2) and M. scutellata (L.) Mill., are considered as fodder or green manure plants in the Mediterranean climate with mild winters (Baddeley et al., 2017) with high biomass characteristics. However, these species are characterized by high nutritional value and produce high-quality and tasty feed for grazing livestock.

Of these species, M. truncatula, which is closely related to M. sativa and is an annual legume, is also; It is a plant used as a model to study the basic biology of legumes in general and the molecular mechanisms of symbiotic N fixation in particular (Benedito et al., 2008; Nandety et al., 2022). M. lupulina, an annual or biennial legume that can yield well even in fine calcareous soils, is used as a green manure by sowing it with cereals and vegetables (co-cultivation). M. polymorpha (Bounejmate et al., 1992), which is commonly found in arid and semi-arid regions in the Mediterranean basin  , is considered a forage plant with a high N fixation capacity (Loi et al., 1995; Ewing, 1999). It is widely grown in Australia for use as fodder and green manure (Yadav et al., 2022). Medicago scutellata also has a high potential to be used as a cover crop in the degraded soils of Mediterranean-type climates, with its symbiotic N fixation capacity and carbon accumulation potentials (Yousfi et al., 2015). Other types of medics that can be used for green manure are; M. arabica, M. laciniata, M. littoralis, M. minima, M. orbicularis, M. rigidula, M. rugosa and M. tornata.

Vetch species (Vicia spp.)

Legumes are the most commonly used species for green manure among forage crops. Among many annual leguminous forage crops, most vetch species, especially the common vetch (Vicia sativa L.) (Figure 3), which is the species that adds the most N to the soil (Couëdel et al., 2018); In addition to producing protein-rich feed with high nutritional value, it is frequently used in green manure applications with its high green manure value (Özyazıcı and Manga, 2000; Long et al., 2004, 2005; Özyazıcı et al., 2009). In the cultivation of vetch species as a green manure plant; Their rapid coating of the soil, increasing soil moisture and organic matter content, reducing soil erosion, especially in autumn, mixing cultivation with cereals and being a sought-after plant of short-term crop rotation systems can be counted as their important advantages. The main types of vetch, all of which are annual and important as green manure plants; common vetch (V. sativa L.), big vetch (V. narbonensis L.), fodder pod (V. faba L.), Hungarian vetch (V. pannonica Crantz.), and hairy vetch (V. villosa Roth.)’ is.

Figure 3. Common vetch (Vicia sativa)

Trifolium species (Trifolium spp.)

The high biological N fixation capacity and the fact that it brings a significant amount of N to the soil in this way have played a role in the use of tripods as green manure, especially in the establishment of organic farming systems (Breland, 1996). Types of triroses used as green manure plants; Meadow Tripod (Trifolium pratense L.), White Tripod (T. repens L.), Hybrid Tripod (T. hybridum L.), Red Tripod (T. incarnatum L.), Persian Tripod (T. resupinatum L.), Alexandrian Tripod (T. alexandrinum L.) and subterraneum (T. subterraneum L.)’ is. Tripods, which are one of the important members of the legume family and have high agricultural value, are important components of green manure in terms of increasing productivity, as they are rich in N and have abundant above-ground biomass and at the same time maintain soil organic matter levels. Meadow tripod (Figure 4), a perennial short-lived species of the trirose, is known as a plant of the northern regions. This type, especially; Estonia (Lauringson et al., 2013), Canada (Angers et al., 1999; Meyer-Aurich et al., 2006) and in the USA (King and Hofmockel, 2017), it is a popular green manure plant and has significant potential in green manure with its high biomass and N yield (Özyazıcı et al., 2021).

White tripod (Figure 5) is an important perennial leguminous plant of temperate pastures with high forage value, high biomass and growth rate, and N contribution through biological N fixation (Nichols et al., 2015). In addition, its wide adaptability and resistance to environmental stresses (Zhao et al., 2022) are some known agricultural characteristics of the white tricoa.

Unlike many other triroses, hybrid tripod is a short-lived perennial alternative forage plant that can be used frequently, especially in organic farming systems, as it is very suitable for acidic and organic soils (Kuusela, 2004). Compared to other types of tricoa, it produces more biomass at lower temperatures (Knight and Hollowell, 1973); Iranian trirose, which is obtained from high-quality dry grass at all stages of its development (Tekeli et al., 2003) and also has more nitrogen than some other legume species and annual mediks (Li et al., 1992); which is very popular with farmers due to its rapid growth, over-formation and production of good quality and quantitative fresh fodder (Khoshgoftar, 1992; Shrestha et al., 1996) Alexandrian trivia; The underground trirose, whose growth in spring is earlier than the commonly used perennial legumes (Teixeira et al., 2017), which can rotate with cereals in areas with low and moderate rainfall (Enkhbat et al., 2022), are annual species with significant potential in green manure applications. Other types of triroses that can be used for green manure are; It can be listed as Gelemen trirose (T. meneghinianum), strawberry trirose (T. fragiferum), sweet clover (T. dubium), rose trirose (T. hirtum) and Caucasian trirose (T. ambigium).

Fodder pea [Pisum sativum ssp. arvense (L.) Poir.]

Forage peas that adapt well to cool and semi-arid climates [Pisum sativum ssp. arvense (L.) Poir.] is an annual cool-season legume forage plant grown for winter (Lal et al., 2018; Özyazıcı and Açıkbaş, 2021). Fodder pea (Figure 6) is an alternative forage plant that leaves a soil rich in N and organic matter to the next crop with its high biological N fixation capacity, suitable for mixed cultivation, and can be grown especially in the winter intermediate period (Özyazıcı and Açıkbaş, 2021). Fodder peas, which offer the opportunity to obtain very high yield and quality grass depending on the climate and soil conditions and the variety used; It is a plant that can be easily used in green manure due to its high biomass and N gain to the soil with its above-ground parts and its low C/N ratio by mixing with the soil in the years when there is no grass shortage.

Plum (Lathyrus sativus L.)

Common damson (Lathyrus sativus L.), which is an annual cool-season legume forage plant, which is used from both grass and grain with high grass and seed yield (Özyazıcı and Açıkbaş, 2019); It is a model crop for sustainable agricultural systems due to its versatile use that can be included in crop rotation and/or mixed cultivation, being a legume species with relatively low input requirements,  It is recognized as an alternative crop to diversify crop growing systems on marginal lands and as a strategic crop that can be used to overcome climate change impacts in the agricultural field (Vaz Patto et al., 2006; Almeida et al., 2014; Gonçalves et al., 2022). It is also superior in yield and N fixation compared to other leguminous plants (Vaz Patto et al., 2006). Although it is used as a fodder crop, cover crop, and green manure plant in many areas similar to the American Great Plains covering many states of the United States, damson has been described as a good alternative to summer fallow (Rao and Northup, 2008; Calderón et al., 2012).

• Lupine species (Lupins) (Lupinus spp.)

These species, which are more tolerant of acidic soil conditions than other legumes, are widely cultivated in temperate regions of the world for grain, fodder, and green manure (Zamora Natera et al., 2017). In Mexico, in various crop cultivation systems,  lupine species such as Lupinus exaltatus, L. rotundiflorus,  and L. mexicanus have been reported to be useful as N suppliers due to their high plant N content and dry matter production (Zapata et al., 2019) and can be successfully used as green manure to increase the fertility of poor, sandy soils (Zamora Natera et al., 2022). White lupine (L. albus L.), yellow lupine (L. luteus L.) and blue lupine (L. angustifolius L.) species are used in soil reclamation of lupines and green manure for beach and poor areas (Meena et al., 2020; Açıkgöz, 2021).

Species of tishclover (Melilotus spp.)

Stone clover (Melilotus spp.) contains two important species with high feed value  , yellowstone clover [Melilotus officinalis (L.) Pallas] and whitestone clover (Melilotus albus) (Darbyshire and Small, 2018). Able to adapt to extreme environmental conditions such as cold and drought (Stevenson, 1969; Al Sherif, 2009) and can also grow in moderately saline soils where many other known leguminous forage crops do not survive (Al Sherif, 2009; Zhang et al., 2016)  These species of the genus Melilotus; is an important soil reclamation, fodder and green manure plant (Baidalin et al., 2017; Chen et al., 2022).

Fenugreek (Trigonella foenum-graecum L.)

Fenugreek (Trigonella foenum-graecum L.) (Figure 7) is an annual leguminous plant commonly cultivated in India and North African countries (Dheri et al., 2007; Güzel and Özyazıcı, 2021). Fenugreek, which is of Mediterranean and Asian origin (Baldemir and İlgün, 2015); It is the oldest known multi-purpose plant with medicinal and aromatic properties, grown for its seeds, fresh stem and leaves (Özyazıcı, 2020). In this respect, fenugreek, which is grown for the consumption of both humans and animals; it is also a plant with green manure potential to enrich soil fertility through N fixation (Rao and Sriramulu, 1977; Duke et al., 1981; Khiriya and Singh, 2003; McCormick et al., 2009). It is a green manure plant that can be used to increase soil organic matter and the amount of N, especially in short-term rotations in areas where intensive horticulture is carried out.

Geven species (Artragalus spp.)

Astragalus sinicus L.,  which is in the genus Astragalus; It is a common leguminous green manure plant that has the unique ability to fix atmospheric nitrogen (N2) into the soil through its nodules at the root, promoting significant accumulation of biomass and nutrients (Guo et al., 2021; Wang et al., 2022a). Many studies  have shown that Astragalus sinucus is an excellent choice as an alternative to traditional N fertilizer and reduces the C/N ratio of substrates, promoting the growth of associated microbial communities and increasing the nutrient content of the soil (Mishra et al., 2001; Zhang et al., 2017; Meng et al., 2019). A. sinicus, a winter legume green manure plant; It is widely cultivated in China, Japan, and other Southeast Asian countries, especially in the paddy-paddy cultivation system (Garrity and Flinn, 1988; Xie et al., 2019; Guo et al., 2021; Yang et al., 2022).

Krotalaria species (Crotalaria spp.)

Crotalaria (Fabaceae) is widely found in tropical and subtropical regions; These plants are widely used in agriculture, mainly folk medicine, cover crops, and green manures, in addition to their use in the management of phytonematodes (da Silva et al., 2022; Rech et al., 2024). One of the most widely used legumes in South Africa exclusively for green manure  is Crotalaria juncea (Mes et al., 1957). Due to its high soil cover and biomass production capacity  , plants of the genus Crotalaria, especially;Crotalaria juncea, Crotalaria ochroleuca,  and Crotalaria spectabilis are proposed to be used for green manure (Berriel et al., 2020; Meena et al., 2020).

Other leguminous crops

Corn cowpea [Lablab purpureus (L.) Sweet] (Açıkgöz, 2021) and soy [Glycine max (L.) Merr.] (Manga et al., 2003), pigeon pea [Cajanus cajan (L.) Millsp.] (Meirelles et al., 2022), forage tree [Leucaena leucocephala (Lam.) de Wit.] (Kang et al., 1981) plants can be used as green manure plants because they provide organic matter to the soil and enrich it with nitrogen. As well as; sesbania species (Sesbania aculeata Retz Poir, Sesbania rostrata Bremek & Oberm.) is a popular leguminous green manure crop used to improve soil health and increase paddy productivity with its high N fixation capacity, especially in Asian countries where paddy production is common (Naher et al., 2020). Sesbanya species also have a wide range of adaptability, with characteristics of resistance to extreme soil conditions such as salinity, alkalinity, and waterlogging (Ghai et al., 1988).

Other plants used in green manure, many of which are legumes of temperate and tropical regions, are listed in Table 1. Table 1. Other commonly used green manure leguminous crops

Kind

Arachis hypogaea L.

Arachis pintoi Krapov. & W.C.Greg.

Calopogonium mucunoides Desv.

Canavalia ensiformis L. DC.

Cassia siamea Lam.

Centrosema pubesscens Benth.

Cyamopsis tetragonoloba L.

Delonix elata L.

Delonix regia (Hook.) Shelf.

Derris indica Lam.

Desmanthus virgatus (L.) Willd.

Dolichos uniflorus Lam.

Glycine gracilis Skvor.

Indigofera tinctoria L.

Lens culinaris Medikus

Macuna aterrima L . Piper & Tracy

Mucuna cinerecum L.

Mucuna deeringiana Bort. Merr.

Mucuna pruriens (L.) DC.

Pueraria phaseoloides (Roxb.) Benth.

Stylosanthes guianensis (Aublet) Sw.

Tephrosia candida (Roxb.) DC.

Vicia cracca L.

Vigna angularis (Willd.)

Vigna sinensis L.

Vigna radiata (L.) Wilczek

Vigna unguiculata (L.) Walp.

Zornia latifolia Sm.

Non-Leguminous Green Manure Crops

This group of plants does not play a role in nitrogen fixation. Non-legumes are mostly; They are used for green manure with their properties such as adding organic matter to the soil, reducing the losses of existing nitrogen, retaining nutrients or reducing nutrient leakage losses, preventing soil erosion, suppressing weeds, and increasing the organic carbon stock of the soil. Non-leguminous green manure crops are listed in Table 2 by species and family.

Dodonaea viscosa

Familya	Tür	Kaynak
Asteraceae	Carthamus tinctorius L. Chichorum intybus L.
	Brassica rapa L.
	Brassica napus L.
Brassicaceae	Brassica campestris L. Raphanus sativus L. Sinapis alba L.
Hydrophyllaceae	Phacelia tanacetifolia Benth.
Malvaceae	Hibiscus viscosa L.
Meliaceae	Azadirachta indica A. Juss
	Avena sativa L.
	Chinese pennisetum L. Chloris gayana Kunth Dactylis glomerata L. Festuca spp. (L.)	Garrity ve Flinn (1988) Rayns ve Rosenfeld (2010) Maitrave ark. (2018) Meena ve ark. (2020)
	Hordeum vulgare L.	Watthierve ark. (2020)
Poaceae	Lolium multiflorum Lam. Lolium perenne L.	Bahadur ve ark. (2022) Lei ve ark. (2022)
	Panicum maximum Jacq. Penissetum glaucum (L.) R. Br. Pennisetum purpureum Schum. Phleum pratense L.
	Secale cereale L.
	Triticum aestivum L.
Polygonaceae	Fagopyrum esculentum Moench
Salvinacea	Azollafiliculoides Lamk. AzoIIa microphylla Lam.
Sapindaceae	Dodonaea viscosa (L.) Jacq.

COMPOSITION OF GREEN FERTILIZER PLANTS AND GREEN FERTILIZER VALUES

For green manure purposes, leguminous forage crops are widely used due to their abundant above-ground structure and high N fixation capacity. These plants, in addition to being a significant source of N; They are also rich in phosphorus and other plant nutrients. The amount of biomass and N that some important legume plants used for green manure use in the soil and the above-ground parts bring to the soil is given in Table 3.

The C/N ratio of green manure plants is also important. The C/N ratio of green manure or crop residue incorporated into the soil plays an important role in the release or immobilization of soil nitrogen (Fageria, 2007). Green manure plants with a low C/N ratio decompose rapidly in the soil and the mineralization of nitrogen increases (Zhou et al., 2019). The release of nutrients in green manure biomass also depends on this mineralization process, i.e. the C/N ratio (Islam et al., 2021).

Most legumes are valued as green manure crops due to their relatively low lignin content and C/N ratio. In this context, legumes, which decompose quickly and in a short time in the soil, leave a good soil and seed bed for subsequent crops and facilitate tillage; they represent an alternative or complementary source of N, which can reduce nitrogen fertilizer requirements. The C/N ratio of some important green manure crops is given in Table 4. When Table 4 is examined, it is seen that legumes have a lower C/N ratio than wheat. If the C/N ratio of green manure is about 25 and the lignin content is less than 15%, it will lead to a rapid mass decomposition and N mineralization.

(Palm et al., 2001). On the other hand, if the C/N ratio of biomass is greater than 25, the immobilization of nitrogen by microbial biomass takes place, reducing its availability for subsequent crops (Gabriel and Quemada, 2011). In addition, Becker et al. (1994) identified the ratio of lignin to nitrogen (L/N) in green manure as another important factor controlling N release.

Abdul-Baki et al. (1996)

Medicago sativa	Alfalfa Lucerne	1.1-5.7	41-300*	Guldan ve ark. (1996) Griffin ve ark. (2000) Talgre ve ark. (2012) Singh ve ark. (2013)*
Medicago lupulina	Black medic	0.6-20.4*	14-459	Stopes ve ark. (1996)
	Yellow trefoil			May ve ark. (2022)*
Medicago pofymorpha	Burr medic	1.63	38.6	Shrestha ve ark. (1999)
Medicago scutellata	Snail medic	0.6-3.1	17-75	Jeranyama ve ark. (1998)
Medicago truncatııla	Barrel medic	2.4-4.5	72-131	Guldan ve ark. (1996)
				Shrestha ve ark. (1999)
Vicia faba	Faba bean	1.8-4.4	55-124	Sincik ve ark. (2008)
				Özyazıcı ve ark. (2009)
				Geren ve ark. (2010)
Vicia narbonensis	Narbonne vetch	Family	Kind	Source
				Brassica rapa
				Brassicaceae
Brassica campestris	Hungarian vetch	Hydrophyllaceae	Phacelia tanacetifolia	Geren ve ark. (2010)
				Azadirachta indica
Vicia sativa	Common vetch	Avena sativa	113-258	Touchton ve ark. (1984)
				Watthieret al. (2020)
				Panicum maximum
				Jeromela ve ark. (2017)
Triticum aestivum	Hairy vetch	Polygonaceae	Fagopyrum esculentum	Abdul-Baki ve ark. (1996)

Guldan et al. (1996)

Ranells and Wagger (1996), Sainju and Singh (2001), Lucie et al. (2015)* Jalilian et al. (2022a)* Jalilian et al. (2022b), Zhouveark. (2022)

*: The relevant source is attributed only to the property to which it is pointed, if there is no asterisk, the source is valid for both properties.

Wang et al. (2022a)

Salvinacea	Azollafiliculoides Lamk.	Toprak üstü biyokütle verimi (KM» t/ha)	Sapindaceae	Dodonaea viscosa
Trifoliunt alexandrinuni	Berseeın clover	3.4-10.3*	84-162	Shrestha ve ark. (1999)
	Egyptian clover			Above-ground biomass yield
				(KM, t/ha)
				Alfalfa
				Black medic
0.6-20.4*	14-459	Stopes et al. (1996)	64-83	Yellow trefoil
Trifolium incarnatum	Crimson clover	May et al. (2022)*	Medicago pofymorpha	Burr medic
				Snail medic
				Barrel medic
2.4-4.5	72-131	Guldan et al. (1996)	12-197	Gulden ve ark. (1996)
				Faba bean
				N’Dayegamiye veTran (2001)
				Soon ve ark (2001)
				Narbonne vetch
				Talgre ve ark. (2012)
				Laurüıgson ve ark. (2013)
				Hungarian vetch
2.5-6.5	62-214	Geren et al. (2010)	17-592	Slopes ve ark. (1996)
				Common vetch
				Ross ve ark. (2009)
				Kanatas ve ark (2020)
Trifolium resupinatum	Persian clover	Geren et al. (2010)	84-160	Özyazıcı ve Manga (2000)
				Hairy vetch
				Ross ve ark. (2009)
Pisunt sativum ssp. arvense	Forage pea	Scientific name	Common	Above-ground biomass yield (KM» t/ha)
				3.4-10.3*
				Mihailovic ve ark. (2007)
Lathyrus safivus	Ross et al. (2009)	0.3-2.0	8*61	Özyazıcı ve Manga (2000)
	Lucie et al. (2015)*			Vaisman ve ark. (2014)
				Mooleki ve ark. (2016)
Lupin us spp.	Jalilian et al. (2022b)	Trifolium hybridum	Alsike clover	2.5-4.7
				2.1-5.7
				Zapata ve ark. (2019)
				Zamora Natera ve ark. (2022)
Lupin us al bus	Ross et al (2009)	Trifoliunt pratense	Red clover	0.6-4.1
12-197	Gulden et al. (1996)	2.M.7	162’	Forbes ve ark. (1970)
				Fowler ve ark. (2004)*
Melilotus albııs	N’Dayegamiye and Tran (2001)	9.7		Chenve ark. (2021)
Melilotus offîcianalis	Soon et al (2001)	2.0-10.2*	18-166	Goplen (1981)*
				Blackshaw ve ark. (2001. 2010)*
				Thiessen Martens ve ark. (2019)
Trigonella foenum-graecum	Laurüigson et al. (2013)	3.8-7.2*	283-291	Gill ve Singh (1988)
				0.6-25.0
				Jalilian ve ark. (2022a)*
				Jalilian ve ark. (2022b)
Astragalus sinicus	Ross et al. (2009)	19.0-37.5**	65-135	Okuda (1953)
				1.7-5.7(1963)
				Gao ve ark. (2018)
				Wang ve ark. (2022a)

de Resende et al. (2003)Sesbania aculeata)(continued)

Bilimsel adı	Ross et al. (2009)	Pisunt sativum	Forage pea	1.3-8.6
		(KM, t/ha)

Crotalaria juncea	Özyazıcı and Manga (2000)	0.9-12.5	23-202	Jeranyama ve ark. (2000) de Resende ve ark. (2003) Mangaravite ve ark. (2014)
Glycine max	Mihailovic et al. (2007)	Lathyrus safivus	Grass pea	0.3-2.0
				Singh ve ark. (2013)*
Lens enli naris	Vaisman et al. (2014)	0.6-2.7	17-64	Brandt (1999)
				2.9-8.2
160-224	Lauringsoi et al. (2013)	12.1-37.0**	98-165	Bhardwaj ve Dev (1985)
(Syn. Sesbania aculeata)	Tngver et al. (2019)			Song ve ark. (2022)
Sesbania rostrata	Zapata et al. (2019)	0.95-5.82	26-181*	Becker ve ark. (1995)
	Zamora Natera et al. (2022)			0.5
				2.M.7
162’	Forbes et al. (1970)	0.6-6.2	16-213*	de Resende ve ark. (2003)

Mangaravite et al. (2014)

Hemândez-Herrerias et al. (2022)*

•: The relevant source is attributed only for the property to which it is pointed. If there is no asterisk, the source applies to both properties. *•: Biomass yield is in wet weight.

Watthier et al. (2020)

Tür	Fowler et al. (2004)*	Melilotus albıis
White sweet clover	9.7	Kir chmann (1988)
Chenve et al. (2021)	Melilotus offîcianalis	Yellow sweet clover
2.0-10.2*	18-166	Goplen (1981)*
Trigonellafoenum-graecum	9.8	Jalilian ve ark. (222b)
Vicia faba	Blackshaw et al. (2001. 2010)*	Özyazıcı ve ark. (2009)
		Gatsios ve ark. (2021)
Thiessen Martens et al. (2019)	Trigonella foenum-graecum	Fenugreek
3.8-7.2*	283-291	Gill and Singh (1988)
Vicia villosa	10.5-12.0	Kuo ve Jellum (2002)
		Jalilian ve ark. (2022b)
Hordeum vulgare	99.1	Lanıey ve Janzen (1996)
Jalilian et al. (2022a)*	27.2-30.0	Kuo ve Jellum (2002)
		Jalilian et al. (2022b)
Astragalus sinicus	Chinese milk vetch	19.0-37.5**
65-135	Okuda (1953)	Adekiya ve ark. (2022)
Penissetum glaucum	28.4	Watthier ve ark. (2020)

IMPORTANCE AND BENEFITS OF GREEN FERTILIZATION

It is possible to list the importance and benefits of green manure as follows:

1. Green manure, in general; It improves the physical, chemical and biological properties of the soil and thus increases soil fertility.
2. Incorporation of green manure biomass into the soil; helps in the accumulation of organic matter, the addition and recycling of nutrients, and the improvement of the hydro-physical properties of the soil; In this way, green manuring greatly improves soil quality and plays a role in maintaining a healthy ecosystem (Jayaraman et al.,

2021; Ansari et al., 2022). Green manuring also ensures that the nutrients in the soil become favorable.

• Green manure prevents soluble nutrients from leaching from the soil and damaging the soil structure by providing ground cover (Islam et al., 2019).
• Organic matter formed as a result of the breakdown of plant residues; It provides better aeration of the soil, water holding capacity of the soils, regulation of water movement in the soil, and more suitable soil temperature.
• Legume plants, which are grown for green manure purposes, especially with a taproot system that can go deep into the soil, absorb nutrients that are suitable at different depths of the soil during their growing processes; When green manure plants are mixed with the soil, these nutrients in the structure of the plant pass back into the soil as a result of the breakdown of the plants in the soil. Thus, as there is an increase in nutrients in the soil, at the same time, the nutrients for the crop to be planted after green manure are converted into a form that can be taken by the plants.
• If plants belonging to the legume family are used for green manure, they convert the nitrogen into a form that the plant will benefit from by binding the free nitrogen of the air to the soil thanks to the Rhizobium bacteria in the nodules in the roots of these plants and living in symbiosis with the plant. Thus, as a result of green fertilization with leguminous plants, the soil is enriched with nitrogen.
• Green manure plants reduce the use of nitrogen fertilizers thanks to the N they bring to the soil (Liang et al., 2022); in fact, in some cases, the inclusion of leguminous green manure plants in the crop rotation can meet the N requirement of the next crop (Sharifi et al., 2014). In this sense, green manure also makes important contributions to the agricultural economy.
• These positive effects of green manures, which are counted as a food source, are a function of synchronization between nutrient release and nutrient demand of the agricultural product, as well as providing an adequate amount of nutrients (Abera and Gerkabo, 2021). In other words, in green manure, green manure plants added and mixed with the soil provide balanced nutrients in almost all development periods of the next product depending on the decomposition-mineralization process in the soil.
• Since leguminous plants used in green manure have low C/N ratios, they promote faster mineralization of nitrogen in the soil (Li et al., 2021).
• Green manure increases the absorption of phosphorus insoluble in the soil and the absorption of phosphorus from phosphorus fertilizer (Ismail, 2013).
• Green manure, which is considered as important indicators of soil quality and fertility (Dai et al., 2019), soils; significantly increases microbial biomass, microbial diversity and their enzymatic activity (Özyazıcı et al., 2010; Sofo et al., 2014; Driver et al., 2014; Chavarria et al., 2016; Nivelle et al., 2016). In this sense, green manure plants provide a suitable environment for the survival and reproduction of microorganisms in the soil.
• Green manures act as a source of carbon and energy for heterotrophic microorganisms (LeBlanc, 2022).
• The incorporation of legumes into the soil as green manure significantly improves key soil quality characteristics such as microbial biomass carbon, unstable carbon, uptake of nutrients (nitrogen, phosphorus, and potassium), and soil aggregations (Ansari et al., 2022).
• Green manuring provides physical protection against soil degradation and thus promotes the improvement of soil structure (Six et al., 2002; Bhattacharyya et al., 2009). They increase the pore volume of soils (Özyazıcı and Özdemir, 2013).
• Green manure plays a role in reducing soil erosion (MacRae and Mehuys, 1985); It helps to prevent the loss of nutrients and organic carbon by being used as a cover crop, especially in ecosystems prone to erosion (Ansari et al., 2022).
• Green manure plays an important role in rehabilitating problematic soils.
• Green manure plants increase the yield and quality of the crops that come after them in the crop rotation (Özyazıcı and Manga, 2000; Wang et al., 2022b).
• Tillage can be minimized by the application of green manure (Garcia-Franco et al., 2015).
• Green manuring prevents the development of weeds in the soil, suppresses them.
• The inclusion of green manure crops in the crop rotation and mixing green manure into the soil is effective in reducing some soil-borne diseases and reduces insect damage in agricultural areas (Larkin and Griffin, 2007; Li et al., 2015; Yang et al., 2019).
• Green manure also has significant advantages in terms of providing additional animal feed. Legume forage crops grown for green manure can be evaluated by burying the root and stubble residues left after being mowed to the grass during periods of grass shortage, and by waiving some of their benefits.
• The application of green manures to agricultural soils reduces the potential for global warming and the intensity of greenhouse gases (Robertson et al., 2000; Zhong et al., 2021). This is of great importance for sustainable agricultural systems.
• Green manure can sustain agricultural production, conserve biodiversity, and reduce soil degradation caused by long-term applications of chemical fertilizers (Asghar and Kataoka, 2022).
• RESULT

The deterioration and losses in agricultural soils, which are under the influence of many factors such as wrong agricultural practices, anthropological effects, global warming, can be reduced and/or improved with green manures and green manure. Green manure, which is the oldest known method of increasing agricultural productivity; With its ability to reduce the load of chemical fertilizers on agricultural soils, provide nutrients to the soil and plants, and increase soil health and crop production, it should be an important component of modern and sustainable agricultural techniques both today and in the future. In this sense, this section; A guide for green manure crops, which is the main element of green manure, is important in terms of providing new information about field management for future applications and research

PART 2

GREEN FERTILIZATION TECHNIQUE AND APPLICATION PRINCIPLES

1. ENTRANCE

Green manure is a product that is mainly used as a soil conditioner and a source of nutrients for subsequent crops (Cherr et al., 2006). The success of green manure approaches for both improving soil structure and production of agricultural products depends on the correct knowledge of the green manure technique and application principles.

Green manure plants buried in the proper circuit have a relatively high nitrogen (N) and moisture content; This provides an ideal source of nutrients for earthworms and microorganisms in the soil. These organisms decompose green manure fairly quickly, and during this process, organic matter and nutrients are ready to be used by subsequent crops (Madge and Jaeger, 2003). For this reason, in order for these and similar effects of green manure to occur, the type and characteristics of the green manure plant are important in green manure applications; Agricultural practices such as the form of green manure, the way the green manure plant is grown, the time and form of bringing it under the ground are also of great importance in providing the desired benefit from green manure. In this section, green manure technique and application principles are emphasized.

TYPES OF GREEN FERTILIZATION

On-site green manure application: It is  the cultivation of the plant to be used for green manure and mixing it with the soil in the application area (Bahadur et al., 2022). In practice, it is a green manure process with legume plants that have green manure value, produce high biomass and have a high N fixation capacity.

Off-site green manure application: It is  the application of green manure by incorporating the leaves and soft green branches of leguminous or non-leguminous plants grown in another field or collected from the nearby wooded, wooded or shrubby area into the soil of another field. It is also generally described as “green leaf fertilization”. This system is usually practiced in central and eastern India. For this purpose;  Species such as Gliricidia maculata, Gliricidia sepium, Calotropis gigantean, Eichhornia crassipes, Leucaena leucocephala, Cassia auriculata, Cassia fistula, Peltophorum ferrugenum are  used (Singh et al., 2013; Bahadur et al., 2022; Kumar et al., 2022). Depending on the softness of the plant parts, they are turned upside down or mixed into the soil 15-30 days before planting the crops that will come after it (Dubey et al., 2015).

Green fallow: The term “green fallow” was coined to describe a green manure farming system, typically intended for the cultivation of green manure plant instead of fallow in a wheat-fallow rotation. In this system, a legume is sown early in the fallow year, buried in the ground during full flowering. The aim is to balance the water and N requirement for the next wheat crop in the crop rotation (Pikul et al., 1997).

Mobile green manure (Cut-and-carry fertilizer) concept: According to this method, which is also known as the “cut-stone legume biome” method and includes the evaluation of legumes as biofertilizers; legumes are grown outside the greenhouse; It is harvested at the appropriate stage, transported and mixed with the soil of the greenhouse field where vegetables will be grown as green manure. A prerequisite for the implementation of this method is the presence of an open area close to the greenhouse to reduce transportation costs of green legume biomass (Gatsios et al., 2021). Mobile green manure application has emerged as an alternative fertilization method that can be used instead of animal manure today. To have a low carbon nitrogen ratio (C/N), mobile green manure must contain legume species with a high leaf-to-stem ratio or be mowed at an early stage of the green manure plant (Palomba, 2016). This method has been tested in many products in recent years (Palomba, 2016; Sorensen and Grevsen, 2016; Van der Burgt et al., 2018; Gatsios et al., 2021).

Alfalfa pellets: It  is an alternative method of mobile green manure. It is the application of alfalfa (Medicago sativa L.) pellets, which are available in the market as animal feed, which do not require the availability of an open area for the production of legume biomass by the grower. This method has the advantage of easy storage and handling compared to fresh biomass. In addition, mobile green manuring enriches the soil with all the macronutrients and trace elements necessary for plant growth. However, the alfalfa pellets method does not have benefits in known green manure practices, such as improving other properties of the soil and reducing plant pathogens (Gatsios et al., 2021). The beneficial effects of alfalfa pellets on N nutrition in canola (Qian et al., 2011), onions (Kaniszewski et al., 2019) and greenhouse tomatoes (Gatsios et al., 2021) have been demonstrated by studies.

Root + stubble green manure: Legume plants used for green manure are not only above-ground parts; At the same time, stubble and subsoil parts that can develop in different soil profiles and go deep into the soil with their strong root systems have an important value. For this reason, in areas where leguminous forage crops are established for green manure, burying the stubble cover and subsoil parts remaining after the green manure plant is mowed for grass in the period or years when there is a shortage of grass is also a kind of green manure application. In both green manure applications, biomass is mixed into the soil to a significant extent and high yields can be obtained in the crops grown after them.

In a study carried out for both grass production and green manure application with big vetch (Vicia narbonensis L.), common vetch (Vicia sativa L.), Anatolian trifolium (Trifolium resupinatum L.), damson (Lathyrus sativus L.), fodder pea (Pisum arvense L.) and white lupine (Lupinus albus L.) species; where all the parts are buried and the grass is removed and only the stubble + root assembly is buried In applications, it has been reported that corn and sunflower grain yields are higher compared to the green manure-no-nitrogen-free application, although it is more common in applications where all green manure plants are mixed with the soil (Özyazıcı and Manga, 2000). Uzun et al. (2005) obtained significantly higher corn grain yields in vetch grass production plots than vetch green manure plots. Sincik et al. (2008) found that common vetch and fodder beans produced an average of 2300 and 2587 kg/ha of above-ground dry matter, respectively, while 120 and 285 kg/ha of root dry matter were obtained from the same products with root parts; They reported that the amount of N brought to the soil by the above-ground and root parts of green manure plants was 49.2 and 2.0 kg/ha in common vetch, respectively, and 58.3 and 5.0 kg/ha in fodder pods. In two different green fertilization applications made by burying all parts and only the root + stubble parts in the soil, the average dry matter weight of the subsoil (root + stubble) and above-ground biomasses of the green manure plant feed pod (Vicia faba L.), the total amount of N added to the soil, the organic C ratio, the total N ratio and the C/N ratio, respectively; 96.8 and 214.5 kg/da, 1.92 and 8.70 kg/da, 32.94% and 46.27%, 1.98% and 4.13%, 16.9 and 11.4%. In both green manure applications with these characteristics, significant improvements were observed in corn and wheat grain yield compared to green manure free treatment (Özyazıcı et al., 2009).  In a study in which Pisum arvense, Vicia pannonica and Vicia narbonensis were used as pre-plants in the winter intermediate period, it was reported that there were significant increases in the green grass yield of silage corn grown after these plants, which produced an average of 4.3, 3.3 and 3.9 t/da of green biomass, respectively, according to the control issue (Kalkan and Avcı, 2020).

METHODS OF GROWING GREEN FERTILIZER PLANTS

Green manure is more effective in areas with regular rainfall. In regions with irregular or low rainfall, the expected results from green manure may not be obtained. In these regions, there may be a decrease in yield in the main product that will come after it, as the green manure plant will use the already low or insufficient water. In addition, due to the scarcity of water in the soil, the decay and breakdown time of the green manure plant will be prolonged. For these reasons; Green manuring annual

It should be applied in areas with an average rainfall of 500-600 mm and regular rainfall or irrigation facilities; It should not be preferred in arid conditions (Soyergin, 2003; Açıkgöz, 2021).

Cultivation method as the main crop

It is a cultivation method in which the field is devoted to green manure plants alone for one year (Aydeniz and Brohi, 1993; Karakurt, 2009). This cultivation method of green manure is mostly applied within a certain planting rotation in order to reduce fallow areas, eliminate soil fatigue and increase soil fertility in fallow areas in Turkey. Green manure plants for this are planted either in autumn or in early spring (such as March); In both cases, mixing into the soil is done in May or June, depending on the development status of the plant. The most important problem of green manure applications in this period may be the drought. In such a case, it is recommended to carry out irrigation in order to get the expected benefit from green manuring and to ensure that green manure plants break down quickly and easily in the soil. It has been reported by Karakurt et al. (2016) that in the fallow-wheat crop rotation system in the Central Anatolia Region of Turkey, when green manure is applied at the appropriate time with the appropriate plant, a grain yield close to or slightly higher than the fallow application can be obtained in durum wheat and an increase in quality is achieved.

However, it should not be expected that the application of green manure as the main product will become widespread. Because the cultivation of a product for a year without any economic return may not be adopted by the producers.

However, in order not to leave the field empty for a year, not to lose the fertility of the soils and to prevent erosion; It should also not be overlooked that in the fallow year, growing leguminous green manure fodder crops and either mowing or grazing the grown crop will be a more acceptable practice by producers.

Cultivation method as an intermediate

It is a cultivation method that covers the planting, cultivation and burial of the green manure plant in the empty winter period between the two main crops. Winter intermediate cultivation is generally practiced in temperate coastal zones. In this method of cultivation, green manure crops are planted in autumn (October-November); Burial in the soil is carried out in April, which will allow the flowering of the plant and the green manure to decompose sufficiently, and will not delay the planting time of the next main crop. For example, in the 5-6 month winter period, which is empty in planting rotation systems such as corn-sunflower, corn-corn, sunflower-sunflower, which are common in the Black Sea Region (Özyazıcı and Manga, 2000; Özyazıcı et al., 2009), it is possible to grow legume forage crops for fodder or green manure purposes on the land that is empty in winter after the main summer crops in the Marmara Region (Uzun et al., 2005). In the Far East countries, where paddy agriculture is common and paddy-paddy cultivation system is applied, paddy + green manure + paddy cultivation rotation system is a highly accepted practice. In these areas where green manure plants are grown as intermediate plants; non-leguminous rye, barley, and wheat, which exhibit high biomass yields, and  N-fixing plant species such as Astragalus sinicus and hairy vetch, are sown immediately after paddy harvest in late fall and then mixed into the soil as green manure before subsequent paddy planting (Hwang et al., 2015).

Method of growing as a lower plant

It is a green manure plant cultivation system in which winter cereals and annual leguminous forage crops are mixed in autumn. Cereals are defined as the upper plant, and green manure plants are defined as the lower plant. For this purpose, annual clovers (mediks) and üçgüls are used (Acar and Ayan, 2000; Karakurt, 2009). During the harvest of the grains, the table of the combine harvester is lifted to the appropriate height so that the lower plants continue their development without being damaged during harvest (Acar et al., 2006). After harvesting the cereals, the remaining green manure plants have developed for a while; In the period of maturity suitable for green manuring, it is mixed into the soil in autumn, taking into account climatic conditions and soil moisture. As a sub-plant, this cultivation method is mostly recommended for places with rainfall above 600 mm (Karakurt, 2009). In the inner regions where the fallow-wheat cultivation system is applied in Turkey, wheat and a suitable green manure plant can be planted as a sub-plant for green manure. In this application, the phenological compatibility of green manure plants and the upper plant is important. In this sense, the upper plant should complete its development as quickly as possible and leave the field in a short time (Karakurt, 2009); the initial development of the lower plant should also be slow (Aydeniz and Brohi, 1993).

Method of cultivation on stubble

This system is based on the principle of planting the green manure plant on the stubble cover left immediately after the harvest of the main crop in the summer. It can be applied in places with abundant rainfall or irrigation opportunities. Planting of green manure plant can be done with stubble planting seeders; In the stubble cover, the upper layer of the soil is first torn with a scratch, and sowing can be done by throwing seeds in the form of sprinkling. In this method of cultivation, green manuring is carried out in autumn or spring. Especially considering the burial process in autumn, it is necessary to choose green manure plant species with a short vegetation period.

Cultivation method in the form of mixed sowing

The use of leguminous and non-leguminous species as green manure plants by mixed cultivation can be a practical option to combine the benefits of individual species. In this way, advantages can be achieved both in mineralization processes and in the supply of nutrients for subsequent products. In this sense, for example; Cereal-legume forage plant mixtures can be considered as green manure due to the high biomass productivity of cereals, the N supply of legumes, as well as the support of legumes with creeping and weak stems. In this cultivation system, the species that make up the mixture are planted in the same row (Tosti et al., 2012) or in different rows next to each other.

Vicia faba var. Beck minor, Vicia villosa Roth., Pisum arvense L., Trifolium squarrosum L., Brassica napus var. oleifera L., Hordeum vulgare L., Lolium multiflorum L., in a study in which the species were grown as lean and mixed green manure plants; It was determined that the amount of above-ground dry biomass of green manure plants grown in mixture was higher than in lean cultivation of the species (Benincasa et al., 2010). In paddy fields in Korea, hairy vetch-barley mixtures are preferred for green manure purposes (Ansar et al., 2010; Lee et al., 2010).

In the green manure study carried out by growing barley and hairy vetch in a mixed state; The highest corn grain yield was obtained from the sowing of hairy vetch alone; This was followed by a mixture fertilization of barley and downy vetch in a ratio of 75:25. In the same study, the highest fruit yield in tomato plant was obtained from the 25:75 mixture of barley vetch (Tosti et al., 2012).

In another green manure study carried out with mixed cultivation of barley and hairy vetch in paddy production; It has been reported that the total above-ground biomass and N accumulation of the mixture are higher than the pure cultivation of the species, and the highest above-ground biomass (8.07 Mg/ha) and N accumulation (131 kg/ha) among the mixtures were observed in the 75% barley + 25% hairy vetch mixture. In the same study, it was stated that all mixtures (75% barley + 25% hairy vetch, 50% barley + 50% hairy vetch, 25% barley + 75% hairy vetch) produced 7-8% higher paddy yield than conventional cultivation (NPK) (Kim et al., 2013).

CULTIVATION OF GREEN FERTILIZER PLANTS AND APPLICATION OF GREEN FERTILIZATION

Plant of Green Manure Crops

After the selection of green manure plants suitable for ecology and cultivation purpose; In addition to good germination and seedling development, seedbed and soil preparation are important to ensure the highest level of soil cover. In other words, as in other cultivated plants, good management is required for a successful establishment and growth in green manure plants. In this sense, good seedbed preparation, sowing time and sowing norm are important.

It is a more common practice to grow green manure crops, usually in the form of intermediate farming. In this system, after the main crop or pre-plant is removed from the field, the soil should be plowed deep with a plow and left in this state for a while. Then, the field is prepared by pulling the disc and rake. Taking into account the existing ecology and the planting time of the plant species used, the seedbed and soil preparation should be completed in accordance with the principles of the normal growing technique of the green manure plant to be used. In determining the planting time of the green manure plant, it is necessary to pay attention to the adjustment of the product to be planted after it in such a way as not to delay the planting time. In this sense, the green manure plant to be planted should be able to reach the maturity to be mixed under the soil at least 3-4 weeks before the planting of the next crop. This period is especially important for the breakdown of buried plant parts in the soil and facilitating the soil preparation of the main product that comes after it. After green manure plants that are not sufficiently broken down and mixed with the soil structure, the planting process will be difficult, and the expected benefit from green manure cannot be fully achieved.

In the coastal zone of Turkey with a temperate climate, green manure plants are planted in autumn for winter, and in the inland regions with harsh winters, they are planted in spring after the risk of frost has passed. However, in spring plantings, it is important to plant on time to ensure good development, before the summer drought restricts growth (Baddeley et al., 2017). In temperate countries where paddy cultivation is common, such as China, Korea and Japan, green manure crops are planted after paddy harvest and green manure is applied before paddy planting in the following season (Kim et al., 2012). In general, large-seeded species are often the best choice for late planting; because they have a higher relative growth rate and do not pose a problem as the rate of seedling development and soil covering will be higher (Baddeley et al., 2017).

During sowing, the basic principle in the amount of seeds used for green manure crops; depending on the plant species, it is kept slightly more than the amount of seed used for grass or grain production (Aydeniz and Brohi, 1993). Sowing can be done with a seeder (Figure 1) or by sprinkling by hand.

In order for green manure plants to produce their own abundant vegetative parts and to ensure their better development and optimum growth, normal maintenance fertilizers should also be given. In this sense, whether they are leguminous plants or other non-leguminous plants; In accordance with the soil analysis of the soils where the green manure plant is grown, it is essential to fertilize over the recommended amounts in terms of the deficient nutrients. For this purpose, other application principles (time, form, etc.) and other maintenance processes of chemical fertilizer are the same as in the general cultivation principles of the green manure plant. However, in regions other than rainy regions, it is recommended to irrigate several times, taking into account the plant-soil relationship, in order for the plants to develop well.

If the plant used as green manure belongs to the legume family; It should not be forgotten that before planting, duly inoculating the soil or seeds with the appropriate bacterial race will be a much more accurate and appropriate approach within the framework of sustainable agriculture. Because, successful N fixation by legumes depends on the availability of the appropriate Rhizobium strain. This is also extremely important in terms of providing the expected benefit from green manure.

Burying the Green Manure Plant

The time of bringing the green manure plant under the ground in the most suitable development period is very important. The purpose of green manure is to mix plant material with high dry matter and at the same time high N content into the soil. The dry matter and N content of plants varies according to their development cycles. As the development period of the green manure plant progresses, the amount of dry matter increases; on the other hand, the proportion of N contained in dry matter decreases. Therefore, the process of green manure; It is recommended to be buried in the ground at the beginning of flowering (10% flowering) in legumes and before the spike in non-leguminous plants (Aydeniz and Brohi, 1993). Even a delay of 15-20 days in the burial process reduces the N content and increases the C/N ratio, fiber, hemicellulose, cellulose and lignin, making it difficult to activate soil microorganisms and break down the material mixed with the soil (Yadav et al., 2013). The appearance of the green manure feed pod mixed into the soil during the flowering period is given in Figure 2.

The process of mixing green manure into the soil is applied in 2 ways. Ploughing the soil after mowing: In order to ensure that the plants are buried in the soil more easily without drifting and to facilitate better decomposition in the soil; First, the plants are mowed with a meadow mower, then mixed into the 0-20 cm layer of the soil using a disc and plow. Ploughing directly: The  green manure plant is broken down on the spot with a disc and buried in the soil by ploughing (Figures 3 and 4). In both cases, care must be taken to annealing the soil to facilitate the tilling and burial process. If the moisture in the soil is low, it is appropriate to carry out a light watering before burying.

Since the majority of biological activity in the soil is generally concentrated in the upper 15-20 cm of the soil, the incorporation of organic residues into the soil should be limited to this depth. The purpose of green manure, plant

It should be to thoroughly mix its material with the soil and slightly bury it below the surface of the soil. The plant/soil mixture must remain moist and aerobic for optimal microbial decomposition of organic matter (Madge and Jaeger, 2003). Green manure performance and its effect on the subsequent crop often vary greatly depending on the type of soil texture. Green manure plant, for proper decomposition; it should be buried to a greater depth in sandy soil and more face-to-face in heavy soils (Dubey et al., 2015).

Agricultural tools that can be used in green manure and their effects on green manure are given below (Knight et al., 2008):

Plow: Does not cut or mix the green manure plant. It is used to turn the soil upside down; hence, it turns the green manure under the soil. Disc harrow: Breaks down the plant and stubble; it does not go deep into the soil, but mixes the green manure well into the soil. Rotavator (Rorotiller): It  is very suitable for breaking down and mixing green manure. It is recommended to use it after the disc is pulled. Cultivators: Good for loosening the soil surface; however, it does not provide much tangling or burial. Chisel plow: It breaks down green manure plants and also loosens the soil; however, it is ineffective for mixing and burying.

Although it also depends on the planting time of the green manure plant, it is important that the embedding process is carried out at the appropriate time in a way that does not delay the planting of the next crop. This process is also important in terms of giving the green manure plants mixed with the soil the opportunity to decompose sufficiently in the soil. In this respect, green manure materials mixed with the soil should be left to decompose for 1-1.5 months. Accordingly, the green manure plant planted in autumn is buried in the soil in April or May at the latest, depending on the development status of the plant. In the meantime, in case of drought, irrigation of the green manure area can also be done to accelerate decomposition. The irrigation process will also facilitate the pre-planting soil preparation of the crop to be grown after green manuring.

Decomposition of Green Manures in the Soil-Mineralization of Nitrogen Sufficient time intervals should be allowed for the complete decomposition of the green manure plant before planning the next crop. This period is related to climatic conditions and the structure of the green manure material (Singh et al., 2013; Dubey et al., 2015). Humid conditions facilitate decomposition. Green manure leguminous plants are irrigated and C/N ratio is quite low compared to wheataceae. When this is combined with soil moisture, it becomes easier for green manures to decompose/break down in the soil. Undoubtedly, the development period at the time of burial of green manure plants is also effective in decomposition. The fresher and more young the green manure plants, the easier and faster they break down. Since the cell wall substances will be high in the later stages of the flowering period, it will be difficult for the green manures to break down in the soil if the burial work is delayed.

The nitrogen brought into the soil from green manure depends on the decomposition rate of green manure and the mineralization of nitrogen. One of the by-products that occur during the decomposition of green manure is ammonia nitrogen (NH4-N). Ammonia nitrogen is converted into nitrate by using microorganisms; The parts that are difficult to break down form the humus part of the organic matter. The release of organic N from green manure is initially rapid, depending on the moisture and temperature of the soil; however, it gradually slows down after about the 20th day (Bhardwaj and Dev, 1985; Khind et al., 1985; Dinesh and Dubey, 1998).

Broder and Wagner (1988) found that soybean residues added to the soil lost 68% of their total biomass within 32 days; Varco et al. (1989) reported that a rapid release of green manure N occurred within 15 days after the incorporation of downy vetch (Vicia villosa Roth); Thonnissen et al. (2000)  reported that Glycine max and Indigofera tinctoria decompose rapidly, losing 30% to 70% of their biomass within 5 weeks of incorporation into soil.

Some researchers have defined nitrogen decomposed from green manure as “fast N” and “slow N”. Fast N, which decomposes immediately after the green manure is embedded in the soil; the other as N, which gradually decomposes over several years. Researchers have reported that the share of fast nitrogen in total N in most green manures ranges from 50-80%, and that 65% of green manure decomposes in the first crop period and 14% in the next crop (Bouldin, 1988; Selvi et al., 2005).

The mineralization rate of nitrogen in green manure; The type of green manure plant, its development stage, the composition of the plant, environmental factors (soil texture, water, temperature, season) and the activity of microorganisms and enzymes affect (Selvi et al., 2005; Elfstrand et al., 2007; Masunga et al., 2016). It has been reported that the soil temperature is in the range of 20 to 30 ^{oC and the soil moisture values are in the range of -0.01 to -0.05 MPa for the rapid release of NO-3 following the introduction of green manure into the soil (Cassman and Munns, 1980). Leguminous green manure species with a C/N ratio in the range of 9 to 16 mineralize faster than other plants, such as wheat species or straw, one week after mixing into the soil (Zhou et al., 2020). In a study comparing species; In terms of N mineralization (ammonium + nitrates),} Avena strigosa + Phaseolus vulgaris and Canavalia ensiformis have been found to be the most promising (with an admixture of 287 and 266 mg/kg of Nminerals, respectively) green manure applications (Hernández-Herrerías et al., 2022).

Efficient management of an agro-system through the use of green manure implies a balance between the availability of nutrients released through mineralization and the requirements of the established crop (Ngetich et al., 2012). For this reason, the decomposition of green manure and this decomposition process are important. Obtaining the maximum benefit from green manure depends on knowing the issues expressed in Figure 5.

e

RESULT

Green manuring plays a very valuable role in agriculture due to the many benefits they provide to the soil and crop systems. As with any crop, green manure plants require good management to successfully plant and grow. In this sense, good seedbed preparation, correct planting and the implementation of other cultural processes in plant growth and development are important. In addition to the usual cultivation of plants, green manuring involves mixing the grown products into the soil. To be able to fully achieve the expected benefit from green manure; The growing period of green manure plants depends on the period and time of mixing under the soil and the decomposition time of the material added to the soil.

THE ROLE OF GREEN FERTILIZATION IN IMPROVING THE PHYSICAL PROPERTIES OF THE SOIL

ENTRANCE

Adding enough fertilizer to the soils in agricultural production does not provide a sufficient increase in crop production. In order for crop production to be ideal, it is absolutely necessary to improve the physical, chemical and biological properties of the soils. The most preferred way by producers to improve these properties of soils is the addition of various organic matter to the soils. Soils are the main source of crop production. Due to very different characteristics, soils with different production potential are intensively cultivated and are affected by many different practices that may adversely disrupt their natural structure. Mankind then has to make both great efforts and great expenses to rehabilitate and improve these lands, which they have degraded and made problematic. It is very important that soils, which are an exhaustible resource, are well managed, not lost, degraded and used sustainably. In other words, the physical, chemical, fertility and biological properties of the soil must be at the desired values and these values must be protected.

In particular, the improvement of the physical properties of soils positively affects the yield and quality of the crop. There are many studies conducted in Turkey and abroad that reveal the accuracy of this issue. The role of green manures in improving soil fertility and providing some of the plant nutrients needed by plants is well known. The addition of organic matter to the soil started with the use of legumes as green manure in China, India and Japan, and was considered an important source of nitrogen (N) in paddy production in wetlands long before the advent of modern agricultural practices (Singh et al., 1991). In North America, green manuring has existed as a farming practice since the eighteenth century (MacRae and Mehuys, 1985). Pieters (1917) reports that green manure studies were found in the source examinations of the research carried out at experimental stations in the United States at an early date. The use of legumes as crops that improve and protect the soil has been an integral part of rotation strategies in history (Pikul et al., 1997).

All other factors being equal, it is certain that a soil with a high level of soil organic matter will have good physical conditions, which will be reflected in production. The effects of green manures on the physical properties of soils are much higher than their effects on all other properties. The improvement of the physical properties of the soils leads to very important positive improvements, from the uptake of plant nutrients to the increase in microbial activity in the soil and the increase in the amount of yield. In this section, the effect of green manure applications on the physical properties of soils is examined.

EFFECTS OF GREEN FERTILIZATION ON SOIL TEXTURE (STRUCTURE)

The solid phase of mineral soil consists of mineral particles that are separate in quantity. The texture, which we call the structure of the soil, consists of mineral particles, which also partially contain organic substances. The solid particles of the soil are generally divided into three groups according to a certain size range. These groups or fractions, called sand, shaft and clay, have a size of less than 2 mm. Texture or structure is a static property that affects many other soil properties. Green fertilization has a significant effect on the structure of the soil and improves the negativities in the soils due to bad body characteristics. In light-natured, that is, sand-based soils; Many negative features such as keeping water in the soil and transitioning to a useful form, absence of plant nutrients, lack of organic matter, poor structural properties, excessive aeration, excess macropores will be eliminated by green manure to be applied to the soils. Green manure, which improves the chemical properties and some physical properties of soils with good physical properties but bad chemical properties such as sand structure, on the other hand, is an important input in improving the physical properties of heavy or clay soils with very good chemical properties but bad physical properties. It is a form of application that is frequently used to prevent compaction and aeration in these soils, to improve structural properties, to regulate the entry and exit of water and air to the soil, to improve the porosity properties and volume weights of these soils.

Green manuring is basically a kind of organic fertilization. Therefore, much more than the benefits of organic matter applied to soils will be provided by green manure, perhaps due to the fact that it is more easily decomposable. Organic matter is an important soil component that provides nutrients to plants, binds the particles in the soil against soil erosion, regulates water and air movement in the soil, and increases the water holding capacity of especially sand-based soils. The increase in the amount of water suitable for organic matter is more evident in soils with sand and loam (Karaman et al., 2007). The fact that organic matter increases the water holding capacity of the soil does not mean that the water supply suitable for plants will increase. It increases the wilting point of soils due to its tight retention of water. The colloidal size of the humus in the structure of organic matter and its large surface area increase the degree of adsorption of the soil (Schlichting and Blume, 1966). Soil texture, along with other parameters, significantly affects the volume weight values, porosity, hydraulic conductivity, tillage and soil moisture parameters of the soils. For this reason, adding natural and artificial organic materials to cultivated agricultural soils is an effective way to eliminate the possible negative effects that may occur on soils after agricultural functions.

EFFECTS OF GREEN FERTILIZATION ON SOIL STRUCTURE AND POROSITY VALUE OF SOIL

According to the soil pore classification, pores smaller than 3 cm allow water to drain. Macro and mesopores of the soil gravitational due to gravity, that is, the drainage of water due to gravity from the soil; Micropores, on the other hand, play a role in the presence of water in the soil that plants can benefit from. While macropores are defined by large pore or pore continuity, mesopores are pores that have less pore continuity but can retain water due to their more convolution.

While green fertilization improves the soil structure, it also has positive effects on the properties of the soil such as water permeability, permeability, infiltration, porosity, volume and weight. Soil structure or soil structure is one of the most important characteristics that affect crop production, since it determines the depth at which the roots can enter, the amount of water and air that can be stored in the soil, and the movement of water and soil fauna. Soil quality is strictly related to soil structure, and most of the environmental damage such as erosion, desertification, and susceptibility to compaction on dense arable land is due to soil structure degradation. In addition, many functions of the soil are also highly dependent on the quality of the soil structure. For this reason, soils with ideal soil structure are also characterized as soils with the widest possible usage area.

In addition to quality parameters such as aggregate stability and hydraulic conductivity, pore area measurements are most commonly used to measure soil structural changes after agricultural activities. In other words, the structural conditions of the soils are closely related to the pore size distributions. Pore area measurements quantify soil structure. Because the continuity of size, shape and pores affects many important processes in soils. In addition to correcting the negative structure properties of the soils, green manures mixed with the soil help the formation of soil structure and, accordingly, the movement of water in the soil from porosity, the formation of impermeable layers, the prevention of crust formation, the ideal movement of water and air in the soil, and the improvement of the soil structure due to the effect of organic matter. It has already been mentioned that although the size of the individual pores is larger in coarse soils, coarse soils have lower total porosity than fine-body soils. Porosity in clay soils is highly variable due to soils wetting and drying, swelling, shrinkage, aggregation, dispersion, compaction and cracking. Finely textured soils have a greater proportion of micropores. Because of this, these soils hold more water and are often poorly drained. Sandy, loamy and clay soils can have total porosity between 30-45%, 40-55% and 45-60%, respectively. The distribution of pores of different sizes is more important for plant growth than total porosity. In soils with a sand structure, most of the pores are relatively large and almost uniform in size, therefore, these pores are easily emptied in a certain suction, while a very small amount of water is retained in the soils. In contrast, in clay soils, the pore size distribution is greater. Water loss is more difficult in soils within this structure. Green manure is an important material that will positively affect the pore size distribution and aggregate stability in these soils, which have both opposite physical properties.

EFFECTS OF GREEN FERTILIZATION ON SOIL VOLUME WEIGHT (VOLUME WEIGHT OF SOIL)

Soil bulk density, which is an indicator of soil volume weight, volume weight or soil compaction, is a very important parameter of soil quality. The volume weight of the soil, which is in a very close relationship with the structural properties of the soil, is also an important parameter for plant production and yield. The addition of organic matter with green manuring helps to stabilize the soil structure, increase the water holding capacity of the soil, and increase the infiltration of water into and from the soil. This value, which is an important determinant of the compactness of the soils, whether the soil is eroded or not, the presence of impermeable layers in the soil, the root movement of the plant, the entry and exit of water and air to the soil, shows positive improvements with green manure and this situation is positively reflected in other features. It is known that soil volume weight or bulk density and aggregate stability are the main factors affecting soil water infiltration rates. This process is also responsible for reducing soil erosion. Water, which can easily enter the soil, will not be able to pass to the surface flow and thus soil loss through erosion will be prevented. Improved soil physical conditions also support root growth and optimal utilization of soil water and plant nutrients. Increasing the soil organic matter content by green manuring is indicated as a reliable index of crop productivity in semi-arid regions, as it positively affects water retention in the soil.

Due to the penetration of the plants used as green manure or cover plants into the soil with their roots during the vegetation period, mixing with the soil when the time comes, breaking down and decomposing, the porosity of the soils will increase and the soil volume weight value will begin to decrease. The low amount of mass per unit volume of organic wastes will cause the volume weight or volume weight of the soil to be low and the mass/volume ratio to decrease. A low volume weight value of the soil also means a decrease in soil compaction

It is considered a positive development because it is. Studies have shown that green manures and crop rotations increase the amount of organic matter, and a measurable increase in soil organic matter quality and other soil quality characteristics is achieved compared to continuous monoculture grain systems. Soil organic matter is a measure of soil quality (Gregorich et al., 1994; Fageria, 2007), as well as environmental quality (Smith et al., 1999; Fageria, 2007). Biederbeck et al. (1994) reported that the accumulation of vegetative residues with frequent inclusion of legumes in rotation improves the physical and biochemical properties of the soil by increasing unstable organic matter.

Barn manure, which is rich in organic matter, is no longer widely used by producers. It is known that the composition of barn manure contains approximately 75% water, 21% organic matter and 4% inorganic matter. The easy availability of barn manure, which is a very valuable input for soils, has become more difficult in the last decade. Both the decrease in livestock in Turkey, the high price and the inability to find barn manure of the desired quality have forced producers to search for a new source of organic matter. The most important of these are green manure plants and green manure. All the known positive properties of barnyard manure such as accelerating the activity of microorganisms in the soil, increasing the amount of organic matter, increasing the water holding capacity of the soil, balancing salinity and pH, preventing soil compaction, etc., can also be achieved by green manure to be applied to the soils.

EFFECTS OF GREEN FERTILIZATION ON SOIL WATER CONTENT AND WATER HOLDING CAPACITY

All the benefits from cover crops used in green manure depend on the cover crop species or mix, soil type, and climate. Leguminous cover crops are generally more preferred due to their short growth period. Winter grains such as oats (Avena sativa L.), barley (Hordeum vulgare L.), triticale (xTriticosecale Wittmack), and rye (Secale cereale L.) can be grown as fodder or green manure. In addition, grains prevent erosion and suppress weeds. When increasing the soil organic matter content is a must, the use of cereals should be a priority due to the relatively high ratio of carbon and N and the slow decomposition of residues. In addition, the large and dense root system of cereals stabilizes soil aggregates, increases aeration in the soil, ensures the storage of soil water, and prevents plant nutrients from going to deep soil layers. Qi et al. (2011) found that winter rye cover crops increased soil water storage in the corn-soybean rotation. Soil management patterns can affect the amount, continuity, conservation and fertility of water stored in the soil. The application of wheat straw residues is considered one of the best ways to increase water retention in the soil and reduce evaporation from the soil (Steiner, 1989; Li and Xiao, 1992; Baumhardt and Jones, 2002). Organic matter application is another way to improve soil properties and therefore increase the water holding capacity in soils (Edmeades, 2003). Growing green manures during the fallow period and ploughing them at a certain time before the next crop planting is a suitable method to increase soil organic matter content and therefore improve rainfall storage efficiency. The most important effect of decomposition of green manure plants is to improve soil properties. This regulates the water/air balance, allowing water to infiltrate the soil and retain plant nutrients in the soil and allow for better root development; This, in turn, leads to better root development. Healing soil physical properties control water retention and water erosion in the soil. In many studies, it has been determined that some organic materials positively affect the physical properties of soils (Canbolat, 1992; Ozbek et al., 1993; Özyazıcı et al., 2011; Özyazıcı and Özdemir, 2013). Compared to single-crop systems, diversified crop rotations typically leave more residues, which can then improve the physical properties of the soil. In organic farming practices, high water infiltration rate is very important for soil water management. In areas where water is limited, it is also very important to reduce the evaporation of water in order to save water due to green manure practices. Mulching or green manure applications are an important soil management practice that can increase water storage in the soil. Especially in dry years, this effect will be much more pronounced.

EFFECTS OF GREEN FERTILIZATION ON SOIL COMPACTION AND WATER AIR MOBILITY IN THE SOIL

One of the important problems of agricultural lands is crust formation and compaction in the soils. The formation of the crust will both prevent the germination of the seed and prevent the entry of water and air into the soil. The water, which cannot penetrate into the soil, will begin to move away from the soil in the form of erosion from the soil surface and carry the soil with it. Green manure or adding organic materials to the soil is one of the most important natural inputs that prevent the formation of crust in the soil. Especially in sloping and weak surface cover, it causes erosion due to surface runoff as a result of the inability or decrease of rain or irrigation water into the soil. Lutz (1952) suggests that soils containing very few miles and fine sand can form a cream layer in almost all types of soils, except coarse sandy soils. The researcher reported that soils that usually contain extremely fine sand and shafts have the ability to form a strong degree of crust. The formation of the shell layer is not only related to the body; At the same time, dispersion rate and aggregate stability values, which are among the factors that accelerate erosion, also affect crust formation. Alfalfa has been shown to significantly improve wet aggregate stability, bulk density, and water infiltration (Su et al., 2009). Alfalfa improves soil properties not only by providing surface cover to soils, but also due to the proliferation of root canals formed over many years. In addition, the benefits of using different rotations of green manure are mentioned to improve the physical properties of the soil in the long term (Garcia et al., 2013). Silva and Rosolem (2001) evaluated the effect of subsurface compaction on root growth of six species of green manure (Avena strigosa, Cajanus cajan, Pennisetum americanum, Stilozobium aterrimum, Sorghum bicolor,  and Lupinus angustifolius).

The researchers found that the density of up to 1.6 Mg/m3 at a depth of 0.15 m      did not restrict the root growth of A. strigosa, C. cajan, P. americanum, S. aterrimum, S. bicolor, and L. angustifolius. Calegari (1995) emphasized the main benefits of the use of green manure as an increase in soil organic matter, reduced evapotranspiration and prevention of erosion by plant residues, their contribution to nutrient cycling, and the degradation of compacted soil layers. Müller et al. (2001) stated that soil compaction is a very common problem in soils, affecting the growth and yield of plants, as well as soil and water balances. To investigate this problem, they experimented with five types of winter green manure (Vicia sativa, Raphanus sativus, Lupinus albus, Avena strigosa and Avena sativa) in four soil profiles (soil heap densities: 1.31, 1.43, 1.58 and 1.70 Mg/m3) with different levels of subsurface compaction. According to the results of this study, which was carried out under greenhouse conditions in São Paulo, using dark red and sand Latosol soil; As soil compaction increases, root length and dry matter increase above the compacted layer, below it decreases, the root system of plants is concentrated near the surface. In the same study, the root mean diameter of L. albus, A. strigosa,  and A. sativa increased in the compacted layer as soil density increased,  decreased for V. sativa, and remained unchanged for R. sativa.R. sativus and A. strigosa performed best on root growth, with higher root length density values in both compacted and subsoil layers and in soil as a whole, even with increased soil compaction. In this study,  it was determined that R. sativus and A. strigosa can be good alternatives to improve the properties of subsurface compacted soils with strong root growth in and below the compacted layer.

Organic matter retains soil water and thus helps the soil recover from compaction. Having enough organic matter in the soil stabilizes the soil structure and makes it more resistant to degradation (Cochrane and Aylmore, 1994; Thomas et al., 1996) and reduces bulk density and soil strength (Sparovek et al., 1999). Agricultural tool machinery and animal traffic working on soils will cause soil compaction; as a result, it will also have a negative impact on the crop production and yield in the soils by reducing the macroporous contents of the soils and the flow of water, heat and gas in the soil (Hamza and Anderson, 2005). Freezing and thawing events in soils generally increase soil compaction. Tillage or green manure practices are frequently used to eliminate this negative compaction in soils (Hamza and Anderson, 2005; Blanco-Canqui et al., 2020).

EFFECTS OF GREEN FERTILIZATION ON SOIL TEMPERATURE

Organic matter and green manures also have positive effects on soil temperature balance. The heating of cold soils and the balancing of the temperature of hot soils are regulated by the addition of organic substances to the soils. Various management regimes applied to soils can change some characteristics of soils. The presence of green manure plants in the soil will make the soils cooler in spring, summer and autumn, while it will cause them to be warmer in winter. Some researchers have emphasized that the soil thermal regime changes with mulching and green manure applications, and that the thermal conditions in the soils where these applications are made are more ideal than in bare soils (Bristow, 1988; Sarkar et al., 2007).

The desired level of soil temperature directly or indirectly affects many events in the soil, from seed germination to yield, from microbiological events to plant nutrient uptake events. The effect of soil temperature on carbon mineralization and N conversion events increases with increasing temperature. In one study, while there was initially high microbial activity in a field where Italian grass was applied, there was a decrease in activity due to the continuation of the mineralization of green manure (Andersen and Jensen, 2001). Mendis et al. (2022) stated that the thermal properties of the soil play a very important role in the soil as they affect the soil temperature and define the soil microclimate that regulates many soil health parameters as well as the life cycles of the soil biota. The study results showed that long-term maintenance of cover crops along with crop systems is necessary in quantifying the effects of cover crops on soil thermal properties. While the deep and fringe roots of the plants used as green manures regulate the soil structure, they have positive effects on the penetration of soil water and air into the soil and their movements in the soil. Soil management practices can change the properties of soils, affecting the soil surface and therefore the thermal properties of the soil. Many researchers have reported that the thermal regime of soils under mulching is lower than that of soils without mulching, that is, it differs from bare soil (Bristow, 1988; Sarkar et al., 2007). Some other researchers have also found that the temperature values of the soils where mulch is applied have increased (Ramakrishna et al., 2006).

EFFECTS OF GREEN FERTILIZATION ON SOIL EROSION

In soils where green manure and animal manure are used, the size of water-resistant aggregates increases compared to those in soils where inorganic chemical fertilizers and synthetic drugs are used. The increased amount of water-resistant aggregate is also indicative of reduced erosion. The green manures used are effective in stabilizing not only the soil surface but also the soils in the lower layers due to their physiological structure and developing root systems. When soils do not have vegetation or when the elements that hold the soil particles together are not in the soil, they begin to move and move to other places with the help of natural forces such as water, wind, gravity, etc. However, laying green manure plants, called green additive plants, or natural materials such as stubble, compost, chipping, etc., on the top surface of the soil will prevent this situation. The proliferation and mineralization of green manures in the environment; It will provide benefits such as preventing soil erosion, absorbing water on the soil surface into the soil and preventing plant nutrients from washing away. If the land is bare, the soil particles will begin to move in the direction of the slope, losing their stability due to the impact of rain droplets on the soil and their kinetic energy. In the following stage, erosion or soil transport will begin. The formation of a crust or cream layer on the soil surface causes erosion due to surface runoff as a result of preventing or partially preventing the entry of rain or irrigation water into the soil, especially in sloping and weak surface cover areas. Crust formation causes significant economic losses as it will cause significant product loss due to the fact that it prevents the seed from breaking this layer and exiting in agricultural lands and does not ensure that the necessary water is stored in the soil. Crust formation emerges as an inevitable danger in clay-heavy and mild-containing soils. The formation of the crust layer is not only caused by the soil structure, but also the dispersion rate and aggregate stability values, which are the factors that accelerate erosion, also affect the crust formation. In other words, the water permeability of the soil, organic matter content, structural properties, and even the type of clay are important parameters for crust formation and subsequent erosion. Organic materials brought to the soil with green manure make it easier for rain to enter the soil. Water entering deep into the soil profile will thus reduce surface runoff and soil erosion, as well as increase the availability of water. Green manure, which is also a kind of mulch, will also prevent the formation of crust on the soils. Mulch, which will also prevent the evaporation of soil moisture, will prevent the impact of raindrops and allow rain or irrigation water to stay in the soil for a long time.

EFFECTS OF GREEN FERTILIZATION ON SOIL COLOR

Although soil color is a morphological feature of soils, it also gives us information about many features of the soil. These colors encountered in soils help to obtain information about such events. Organic matter, which is usually concentrated in the upper layers of soils, corresponds to only a few percent of the mass of soil organic matter. Organic matter, i.e. green manure, has a significant impact on all soil functions and plays a central role in the global carbon cycle. Therefore, the carbon content or dark color value is a differentiating criterion for soil definitions in German and international classifications.

USE OF GREEN FERTILIZATION IN SOIL IMPROVEMENT

Green manure is used as an agent not only to develop a soil with good physicochemical properties and to make it more productive, but also to improve saline and alkaline soils. Alkaline soils are generally soils poor in organic carbon. Green manures to be added to these soils are important because they bring organic matter to the soil when they replace fallow. The sesame plant improves the hard structure of the soil like concrete and is a kind of fertilization of barren and salty alkaline soils. Vakeesan et al. (2008) found that tamarind (Tamarindus indicus) leaves

They emphasized that it is an ideal plant for improving soil salinity in the coastal areas of Lanka. Nature-hardening tamarind leaves form an ideal structure for soil microbes.  They stated that green manuring of Pavetta indica, Thespesia, Azadirachta indica and sun hemp is also good for salinity. After these processes, the presence of calcium ions in the soil is replaced by sodium ion in this type of alkaline soil.

RESULT

The soil property in which green manures are most effective is physical properties. With the improvement of the physical properties of the soils, positive effects occur in other soil properties and, accordingly, in plant production. Because, with the increasing root development as a result of the improvement of the physical properties of the soil, the plant can use soil water and nutrients more. Green manures have important effects on soil structure, structure, porosity, volume weight, water holding capacity, soil compaction, aeration, temperature and color. In addition, water erosion is also controlled in green fertilized soils. Green manures are also used in the reclamation of saline and alkaline soils that have somehow lost their productivity.

CHAPTER 4

THE ROLE OF GREEN FERTILIZATION IN IMPROVING THE CHEMICAL PROPERTIES OF SOIL

ENTRANCE

The chemical properties of the soil are shaped by various soil formation events that take place during the decomposition and transport of the parent material on which the soil is formed. Therefore, the chemical structure of rocks and minerals and the intensity of their weathering processes are the main determining factors on the chemical properties of the soil. While the decomposition of rocks and minerals containing high levels of silicates (SiO2) such as quartz and feldspar causes the formation of acidic soils and poor in plant nutrients; With the decomposition of rocks and minerals high in magnesium and iron, such as olivine, pyroxene and amphibole, soils with a basic character and richer in plant nutrients emerge. Limestones are carbonates rich in calcium and magnesium that decompose relatively easily. The presence of these carbonates in the soil significantly affects the chemical properties of the soil. The main materials, which include limestone, cause the formation of soils of a basic character due to the abundance of basic cations.

The parent material, which is the material on which the soil is formed, also determines the amount and type of clay minerals present in the soil. Clay minerals have important effects on the chemical properties of the soil due to their unique chemical structure. Both clay minerals and the organic matter of the soil are called soil colloids because of their extremely small size and high surface area. Due to these properties, soil colloids have very close relationships with plant nutrients dissolved in water and soil solution. Furthermore, both colloids have negatively charged surfaces, and this common property results in the adsorbing of important nutrients (cations) for plant growth on their surfaces. Important cations adsorbed by soil colloids; ammonium (NH4+), calcium (Ca2+), potassium (K+), magnesium (Mg2+), iron (Fe3+), copper (Cu2+), zinc (Zn2+) and manganese (Mn2+). Cations that are attracted and adsorbed to colloidal surfaces are called changeable cations because they can easily exchange with other cations dissolved in soil solution and can be taken up by plant roots and soil organisms.

The total amount of exchangeable cations that a soil can adsorb is called the cation exchange capacity (KDK). The unit of the KDK is me/100 g of soil. The KDK of soils varies between 3-50 me/100 g. The cation exchange capacity of the soil is an important soil parameter; Because it gives an idea of the amount of useful plant nutrients. It also plays an important role as a buffer against the change in soil acidity. Since the concentration of cations adsorbed to soil colloids is 10-100 times higher than the concentration of cations in the soil solution, the leaching of exchangeable cations in surface soils into subsoil layers or drainage waters is significantly reduced. While washing is higher in sandy soils with low cation exchange capacity, the leaching of nutrients from loam or clay soils with high CRK is very low (Ahmadpour et al., 2015).

The chemical properties of the soil are also important in terms of fertilization. pH has a significant effect on the usefulness of the nutrients added to the soil by fertilization and present in the soil. The balance between cations and anions taken up by plants affects the pH of the rhizosphere. As a plant takes in large amounts of ammonia, one of the main sources of nitrogen (N), protons secreted by the roots acidify the soil around the root. As they take in nitrate (NO3-), which is another main source of N, the roots secrete OH- or HCO3^–, which increases the pH of the rhizosphere. NO3^– and NH4+ are useful N forms that plants can take. For every 1 mole of NH4+ taken by the plant, 0.9 moles of H+ are released, while for 1 mole of NO3- ingested, 0.1-0.3 moles of OH^–  are released. The pH of the rhizosphere may vary depending on the form and concentration of the fertilizer, and the degree of pH change around the root may vary depending on the buffer capacity of the soil (Kant and Kafkafi, 2013).

Organic matter, which is an important chemical property of the soil, has important effects on plant growth and yield. The nutrients in the organic matter pass into the soil solution with a slow release rate; This, in turn, causes the plant to benefit from these nutrients for a longer period of time. Organic matter also promotes chelation of microelements, increases the buffering capacity of the soil (resistance to pH change) and anion and cation exchange capacity, and reduces the leaching potential of nutrients (Weil and Magdoff, 2004).

Various forms of soil management affect the chemical properties of the soil in different ways. Green manure, which is made to increase the amount of organic matter in the soil, has effects not only on the organic matter of the soil, but also on other chemical properties. In this section, the effects of green manure on the chemical properties of soils are emphasized.

THE EFFECT OF GREEN FERTILIZATION ON THE AMOUNT OF ORGANIC MATTER OF THE SOIL

The primary and most important benefit of green manure, which helps to obtain more and quality products by increasing the fertility of the soils, is the enrichment of the soil in terms of organic matter. Especially in places where barn manure is scarce, the organic matter content of the soil can be significantly increased by green manure (Karakurt, 2009).

Soil organic matter (TOM) consists of plant and animal residues mixed with the soil in various ways, and complex compounds formed by their decomposition and decomposition products as a result of various chemical reactions. Although mineral soils are relatively small compared to other soil components, organic matter has important effects on all soil functions and plays a central role in the global carbon (C) cycle. Due to its large surface area, the organic matter of the soil is an important sorbent for organic and inorganic substances in the soil solution. Due to having a negative electric charge, they increase the cation exchange capacity of soils and also have hydrophobic areas that can bind poorly soluble organic hydrophobic substances. It also has an important role in the development of stable soil structure by providing the formation of micro and macro aggregates. Organic matter is effective on the color of the upper soil layer and the heat balance in the soil, especially in agricultural soils. The nutrients released by the mineralization of vegetable wastes are an important source of nutrients for plants and microbial biomass. Finally, organic matter is an important source of C and energy for soil fauna and microflora. Always a high biological activity; It requires the addition of new plant and animal wastes as much as the amount of organic matter that is constantly decomposed into the soil (Okur, 2021).

There are 3 types of TOM pools in the soil. These; 1) Active (Labil) TOM: Microbial biomass + fresh organic wastes, 2) Slow (Long-term) TOM: Organic compounds released from active TOM, partially preserved and 3) Stable (physically protected) TOM: Physically preserved humus that is extremely resistant to decomposition. To create an active TOM pool in the soil; immature organic wastes (proteins, high glucose content) with high amounts of water-soluble N and C should be given to the soil. Organic materials with a C/N ratio of less than 24 decompose and mineralize rapidly in the soil. Organic materials with a C/N ratio greater than 24 need an additional nitrogen for decomposition; however, these wastes stay in the soil for a longer period of time, contributing more to the TOM. In order to support the slow TOM pool of the soil, vegetable waste and fertilizer should be applied to the soil continuously. Dead plant roots, in particular, are extremely important for slow and stable TOM. Legumes, with their large root system and above-ground parts, increase the formation of slow TOM. In particular, alternations with forage crops (such as alfalfa, vetch) from the legume group are very effective on slow TOM.

In contrast to other organic practices, a large proportion of the C input from green manure plants is added to the soil as roots, which contributes to the stable carbon pool more effectively than the above-ground C-input (Kätterer et al., 2011). Furthermore, increased soil organic carbon can increase the C input of the parent plant, having a positive effect on plant growth (Brock et al., 2011). Especially in irrigated areas where intensive vegetable cultivation is carried out, winter annual legumes such as vetch and broad beans are planted in November and when mixed with the soil at the beginning of May, during the flowering period, they leave organic matter equivalent to 2 tons of farm manure and N equivalent to a bag of 26% ammonium nitrate fertilizer (Aşık and Katkat, 2018).

Legumes are able to fix a significant amount of atmospheric nitrogen and increase the amount of organic matter in the soil. Non-leguminous plants, on the other hand, contribute to an increase in the amount of stable organic matter in the soil. With the use of these two plant groups together, both the amount of organic matter in the soil increases more and the soil is enriched in terms of N (Tejada et al., 2008).

The effects of green manure applications on wheat (Triticum aestivum L.) yield and labile and humic fraction of organic matter in soil were investigated by N’Dayegamiye and Tran (2001) for 5 years. In this study, meadow trirose (Trifolium pratense L.), buckwheat (Fagopyrum esculentum L.), millet (Echinicloa crus-galli L.), mustard (Brassica hirta Moench) and rapeseed (Brassica campestris L.) plants were applied as green manure; It has been reported that green manure applications significantly (p<0.01) increase the total C and N amounts in the soil and soil respiration, and the highest increases were realized in mustard, rapeseed, millet and buckwheat applications. Çengel et al. (2009) determined that barley + vetch application was the most effective green manure application in increasing the total amount of organic C in the soil, and barley + vetch and broad beans + vetch applications were the most effective in increasing the total amount of organic C in the soil. Özyazıcı and Özdemir (2013) used fodder pods as green manure under the green manure-corn-wheat rotation system under the conditions of Çarşamba Plain. In this study, in which two applications were made as burying the entire part of the green manure plant and only the root + stubble part, it was determined that both green manure applications increased the soil organic matter content compared to the control. However, in the same study, it was also reported that the effect was temporary and limited due to the rapid decomposition of organic materials due to the conditions of the region. Duyar (2014) investigated the effects of green manure and green manure + chicken manure applications on the yield and fruit quality of organic tomatoes grown in the greenhouse after the production of head salad and as summer green manure; soybeans (Gylcine max L. Merr.), forage cowpea (Vigna sinensis L.) and corn (Zea mays L.). The researcher found that the soil organic matter content after harvest (dismantling) in the first and second years of green manure + chicken manure application.

26.22% and % respectively                                                Increased by 10.40 percent

has determined.

THE EFFECT OF GREEN FERTILIZATION ON TOTAL NITROGEN AND OTHER PLANT NUTRIENT CONTENTS OF THE SOIL

When the amount of organic matter in the soil is increased with green manures, the amount of useful pools of plant nutrients in the soil also increases. Because with the decomposition of organic matter, all organically bound nutrients in its structure pass into minerals, that is, in a form useful for plants. Due to their high N content and low C/N ratio, legumes are an important source of N for plants. The amount of N entering the soil with green manures can accumulate at levels that can meet some or a significant part of the N needs of the next product. These high amounts of N and other plant nutrients, which come through biological N fixation, are released into the soil at a slow rate. In this way, N and other nutrients useful for the plant are provided by green manure for the next crops to be planted/planted in the soil (Freyer, 2003). N’Dayegamiye and Tran (2001) found that green manures increased the N uptake of the wheat plant, and their contribution to the amount of N in the soil decreased in the form of rapeseed > millet, > mustard, >alfalfa > buckwheat. It has been determined that grains planted as second crops of legumes have significant effects on grain yield (Olesen et al., 2007). In paddy agriculture, where chemical fertilizers are used intensively, environmental pollution can be prevented by green manure, and the N need of the plant can be met in this way. The amount of N introduced into the soil by green manuring ranges from 30-100 kg N/ha, and in many cases between 50-60 kg N/ha (Ladha et al., 1988).

Perennial legumes such as alfalfa, with their deep root systems, ensure that significant amounts of other nutrients besides nitrogen enter the soil. Green manures due to increased microbial activity and decreased redox potential; They also increase the mobility of other nutrients such as sulfur (S), phosphorus (P), silicon (Si), Zn, Cu, Mn (Teit, 1990). Some researchers suggest that vegetable wastes and green manures are not rich in potassium and especially phosphorus (Maiksteniene and Arlauskiene, 2004). But green manures stimulate microbial activity by correcting the physical and chemical properties of the soil. Due to the increased rate of decomposition in these conditions, organic P and K in green manure are converted into useful forms and contribute to the nutrition of the next crop (Askegaard and Eriksen, 2008; Eichler-Löbermann et al., 2009).  Green manure with Sesbania rostrata increased both the beneficial amounts of Fe, Mn and Cu in the soil and the amounts taken up by the plant. Researchers have attributed this to the development of intensely reduced conditions, complex formation, and greater nutrient binding capacity (Bhattacharya and Mandal, 1997).

THE EFFECT OF GREEN FERTILIZATION ON OTHER CHEMICAL PROPERTIES OF SOIL

The decomposition of green manures mixed with the soil occurs faster in soils with a neutral reaction. This is due to the fact that the vast majority of microorganisms living in the soil show optimum growth at a pH of 6.5-7.5. Organic acids and carbon dioxide (CO2), which are produced during the decomposition of green manures, can slightly reduce the pH of the environment. The decrease in soil pH can also occur during the development of green manures. As a result of the anion and cation balance deteriorated due to the ammonium entering the plant with ammonium uptake or N2 fixation, the protons (H+) secreted by the plant roots acidify the soil around the root. This feature of green manures is used in the improvement of alkaline soils (Harris, 1995).

With green manure applications, the amount of changeable cations in the soil and the CRAs also increase (Austin et al., 2017; Wang et al., 2017; Roy et al., 2018). De Melo et al. (2019) stated two important benefits of including vegetative wastes in the soil profile as follows; (i) improving the nutritional status of the plant by improving the plant nutrient cycle, and (ii) generating a positive plant-soil feedback of the sequential use of plant species used as green manure.

Dos Santos Nascimento et al. (2021) found that plants of the Poaceae family (eg; Brachiaria decumbens and Pennisetum glaucum) while supporting soil pH, Ca2+, K+, KDK and useful water capacity in the soil; Plants of the Fabaceae family (eg; Canavalia ensiformis, Crotalaria juncea, Crotalaria ochroleuca, Crotalaria spectabilis, Lablab purpureus, Mucuna pruriens, Neonotonia wightii and Stilozobium aterrimum) H++Al3+, KDK, have been found to increase the capacity of useful water and useful water in the soil. These results show that green manure has a positive effect on soil fertility, soil water content and nutrients.

Organo-mineral complexes have a significant effect on the formation of water-resistant aggregates in all soils. These colloidal complexes have beneficial effects on both the physical and chemical properties of the soil. About half of the organic matter entering the soil by green manure is used in the formation of organo-mineral complexes (Chen and Wang, 1987). In the process of decomposition of green manures, polymers are formed with a significant amount of negative electrical charges, some of which are insoluble in water with a low molecular weight. These substances form complexes with clays through metal ions in the soil. These complexes are able to protect organic molecules in their structure against microbial decomposition for a long time. Organo-mineral complexes increase the stable TOM quality of the soil (Okur, 2021).

RESULT

As a result, we can say that green manure applications are an important soil management option to increase organic carbon and other element stocks in agricultural soils. Green manure should be applied to the soil in a sustainable way to support the active, slow and stable organic matter pools of the soil. Green manuring is also attracting the attention of many researchers as an impressive measure in mitigating the negative effects of climate change. Compared to natural and semi-natural vegetation, organic C losses are 30-40% higher in cultivated soils. In order to stop and reduce these carbon losses, forms of management that provide organic matter to the soil, such as green manure, have become more important. Research on the medium- and long-term effects of green manure plants on soil’s organic C stocks is still needed.

CHAPTER 5

THE ROLE OF GREEN FERTILIZATION IN IMPROVING THE MICROBIOLOGICAL PROPERTIES OF SOIL

ENTRANCE

All living things that live in the soil and have a relationship with the soil are called soil biota (edaphone). These organisms, which are defined as biological engineers who carry out and transform the physical, chemical, biological and ecological processes in soils, have the potential to change and improve soil properties and soil quality. These functions of soil biota are considered to constitute vital activities that are considered part of the biological indicators of soil health. These creatures are; They serve to ensure the sustainable functioning of all ecosystems with a wide range of basic services such as performing nutrient cycles, regulating soil organic matter dynamics, carbon (C) sequestration and gas emissions in the soil, modifying the physical structure and water regimes of the soil, increasing the efficiency and amount of nutrient uptake of plants, increasing plant health and protecting soil quality (Okur, 2021).

The management of agricultural soils and the practices applied affect the soil biota in various ways. Green manure is also an important form of management that increases the number and diversity of microorganisms in the soil due to its easy decomposition due to its high nitrogen (N) content. In addition to having a direct effect on soil microorganisms by providing an important source of energy and carbon, green manure has indirect effects on these creatures with its improvements in the physical and chemical properties of the soil. In this section, the effects of green manure on the microbiological properties of the soil are examined.

DIVERSITY OF SOIL ORGANIZATIONS

Soil organisms are divided into the following classes according to their size;

1. Microflora and Microfauna: Organisms smaller than 100 μ (Bacteria, actinomycetes, algae, fungi, protozoa, etc.)
2. Mesofauna: creatures with a size of 100 μ-2 mm
3. Macrofauna: creatures 2-20 mm in size
4. Megafauna: creatures larger than 20 mm

Microflora (bacteria, archaea, fungi and algae) and microfauna (protozoa and nematodes) make up the majority of organisms in the soil. Due to their wide range of metabolic activities, bacteria play a key role in the cycle of nutrients in soils. Dinitrogen-fixing bacteria introduce nitrogen into the soil ecosystem through biological N fixation. Nitrifying bacteria convert ammonia into nitrate, creating an N form that plants can benefit from, but is also susceptible to leaching and denitrification. Bacteria also play an important role in the cycles of elements such as phosphorus (P) and sulfur (S) in soil. Bacteria metabolize sugars, starch and simple proteins in soil organic matter very quickly; However, they decompose lignin, waxes and oils in vegetable tissues much more slowly. These resistant compounds form soil humus. Humus, on the other hand, is an important component that improves soil structure and increases the amount of water and nutrient retention in the soil. Bacteria also contribute to soil formation and soil structure by creating acids and secretions that decompose soil minerals. In addition, due to the polysaccharides formed by bacteria, soil particles bind to each other and stable aggregates are formed.

Archaea are creatures that have the ability to live in very extreme conditions such as extreme heat and extreme salt, which were discovered in the early 1970s. Some archaea live at high temperatures, such as in geysers or seabed hot springs, often above 100 °C. Others are found in very cold environments or in extremely salty, acid, or alkaline environments. There are also archaea living in temperate conditions (mesophyll). They are found in swamps, seawater, soil and wastewater. Archaea are generally harmless to other organisms and have no known disease agents. Archaea are divided into three groups according to their preferred habitat: 1) Extreme Halophiles (Salt Lovers), 2) Methanogens and 3) Hyperthermophiles.

Fungi, with their developed (eukaryotic) and larger cell structures, are more abundant in soils than other groups of microorganisms on a weight basis. Their biomass ranges from 500-5000 kg/ha. Fungi can live almost anywhere that contains suitable organic substrate. In many cases, they are vital to ecosystem function and viability. Saprophytic fungi, which break down dead organic matter, play an important role in soil mineralization events such as ammonification and carbon cycling. Fungi are generally obligate aerobes and are more common in acidic soils where there is less competition with bacteria. Saprophytic fungi are primarily responsible for the decomposition of cellulose, hemicellulose and pectin together with bacteria. Lignin, the fourth most common compound in vegetative tissues, is decomposed mainly by fungi.

Almost all soil algae live in the top layer of soil in terrestrial ecosystems. They are green in color because they contain chlorophyll. However, some algae appear brown or red because they contain other pigments that mask the green color, such as xanthophylls and carotenoids. Algae are photoautotrophic organisms and vary greatly in morphological, physiological, reproduction and habitat. Algae are divided into two main groups: Eukaryotic algae and Prokaryotic cyanobacteria (previously known as blue-green algae). Many cyanobacteria can perform asymbiotic N fixation by reducing molecular nitrogen to ammonium nitrogen. Some cyanobacteria, on the other hand, establish N fixation by establishing symbiotic relationships. For example, Anabaena azollae performs N fixation by establishing a symbiotic relationship with the Azolla plant.Azolla is an important source of N in paddy production. In tropical rice ecosystems, approximately 50 kg N/ha per year can be provided with these creatures (Okur, 2021).

FUNCTIONS OF SOIL ORGANIZATIONS

Soil organisms have important roles in soil decomposition and transformation. Some events in which soil organisms are effective; 1. Decomposition and transformation of organic matter, 2. Formation of humic substances, 3. Structure formation, 4. Redox reactions and 5. It is the detoxification of waste materials. Soil microorganisms have the ability to decompose and transform all organic substances that come to the soil in some way. An exception is unnatural synthetic substances, which we call xenobiotics. Some of these substances can actually be decomposed very slowly by soil microorganisms. Since many microbial processes in soil are carried out by taking and giving away electrons or protons, microorganisms also have important roles in oxidation/reduction (redox) reactions in soil. Soil fauna contributes to the decomposition of the litter layer (the layer consisting of plant leaves and stems at the top of the soil) and the formation of structure. They also influence the species composition of microbial and animal presence in the soil, depending on dietary choices.

Soil organisms have important roles in the cycles of elements in the soil, especially C and N. During the decomposition of organic wastes that come to the soil in some way, soil microorganisms and fauna use the carbon in organic wastes in cell construction (Assimilation). Fungi incorporate more carbon into their cells than bacteria. The mineralization of organic waste under aerobic conditions results in the formation of carbon dioxide (CO2) and water. In anaerobic conditions, organic compounds decompose slowly gradually through events such as nitrate reduction, sulfate reduction, fermentation, methanogenesis, acetogenesis.

Carbon in the atmosphere; On the one hand, it is used by plants and microorganisms to make biomass, and on the other hand, the amount of carbon used is released back into the atmosphere. This balance in the carbon cycle in nature was established after the 1950s with the use of fossil fuels, wrong land use and deforestation.

and the amount of CO2 in the atmosphere increased from 280 ppm to 400 ppm (Okur, 2021).

Soil microorganisms play an executive role in the conversion reactions of nitrogen, which can be found in organic, inorganic and gaseous form in the soil. Some bacteria can convert dinitrogen to the ammonium form by N2 fixation (Biological N2 fixation). Apart from this, nitrogen can also transform from one form to another by ammonication/immobilization, nitrification and denitrification events carried out by microorganisms.

Soil organisms use oxidation-reduction reactions to produce the energy necessary for their metabolism. Some of the soil microorganisms oxidize reduced inorganic compounds under aerobic conditions and use this reaction to form adenosine triphosphate (ATP). In oxygen-free conditions, oxidized inorganic compounds are reduced by soil microorganisms. The metals that can be oxidized and reduced by soil organisms are iron (Fe), manganese (Mn), mercury (Hg), arsenic (As), selenium (Se), chromium (Cr), and uranium (U) (Blume et al., 2016).

Soil organisms also have an impact on the stabilization of soil structure. Soil algae and cyanobacteria form mucilage (glue-like secretion) in the top layer of young soils a few mm and in desert soils to protect themselves from drought and other competing microorganisms. The formation of mucilage improves the structure of surface soils and protects the soil from erosion. Various bacteria

by                                  Secreted                      extracellular                    polysaccharides,

It serves to attach microorganisms to various surfaces (such as plant roots, humus and organo-mineral particles) and to be recognized by host organisms, and also helps to protect them from harmful substances and drought. Such secretions serve to form microaggregates (250 μ <) in the soil. Fungi and fine roots also accelerate the stabilization of the soil structure with their branched structures that form a wide network in the soil.

Soil fauna, on the other hand, affects the soil structure through secretions from the digestive system and bioturbation. Earthworms mix the organic and inorganic compounds of the soil in their digestive systems and serve to form clay-humus complexes. These complexes increase the structural stability of the soil. The droppings (kest) of earthworms are rich in microorganisms that accelerate decomposition events.

Soil organisms react when they encounter organic pollutants (such as oils, pesticides) either in the form of a decrease or an increase in their metabolic activity. Organic pollutants biodegrade in a series of enzymatic ways. In complete decomposition, it decomposes the pollutant into CO2 and water (biomineralization). Under sub-optimal environmental conditions (e.g. oxygen-free conditions), organic pollutants can only partially decompose (biodegradation).

EFFECTS OF SOIL MANAGEMENT FORMS ON SOIL ORGANIZATIONS

Soil microbial biomass and enzyme activities respond more quickly to changes in soil management practices than to other soil properties (such as organic matter). The main applications made to the soil in the use of soil for plant production and the reaction of soil biota to these applications are listed below.

Cultivation of Soils

The way and frequency of soil cultivation affects soil organisms in various ways. Turning (ploughing) the soil leads to a homogeneous distribution of nutrients and organic substrates in the surface layer of the soil. After ploughing the soils, soil microorganisms take advantage of this due to better aeration and a better distribution of organic substrates. On the other hand, many soil animals, such as earthworms, either die or lose their habitat due to the destruction of their nests as a result of intensive cultivation of the soil. Terrapinning of soil has lasting effects on the functional diversity of earthworms.

Reducing the intensity of tillage leads to an increase in soil microorganisms and nutrient resources in the uppermost soil layers (0-5 cm and 0-10 cm). The cultivation of soils also changes the distribution and function of soil microorganisms throughout the soil profile. Conservation tillage techniques increase the number of earthworm species (such as Lumbricus terrestris) that feed on nutrients on the soil surface but live in the subsoil  layers. The permanent tunnels opened by these worms cause rainwater to infiltrate the soil more quickly, which contributes to the reduction of erosion. In general, the presence and diversity of many soil animals are increasing due to the decrease in tillage intensity. Therefore, an important goal of conservation tillage is the conservation and activation of soil biota.

Organic and Mineral Fertilizers

Organic and mineral fertilization directly affects soil organisms with the addition of plant nutrients to the soil and indirectly with the increase in plant growth. The reaction of soil microorganisms to these applications varies depending on the type, quality and amount of fertilizer. Studies have shown that animal manure applications stimulate soil microorganisms more and increase microbial biomass compared to mineral fertilizers (Kandeler, 1999; Okur et al., 2016). Not only the amount but also the quality of the organic fertilizer applied to the soil has an effect on the reaction of soil microorganisms. In a soil where the same amount of organic fertilizers (green manure, animal manure and peat) were given, the organic material that increased the organic matter of the soil the most was peat, while animal manure increased the microbial biomass more (Kirchmann et al., 2004). At low pH degrees, the dominant group of microorganisms in the soil changes in favor of fungi. Fungi contribute more carbon to their biomass than bacteria, and therefore these organisms use carbon from organic fertilizers more effectively than bacteria. In soils where fungi are dominant, carbon accumulates for a longer period of time.

Pesticides

Pesticides can directly or indirectly affect soil organisms. In direct action, pesticides can bind the active centers of enzyme systems in microorganisms in a reversible or irreversible manner. If pesticides alter the species composition and number of the microbial community in the soil, then this effect is an indirect effect. Generally, the degree of bioavailability of pesticides determines the intensity and duration of the inhibitory effect on non-target organisms. Insecticides have negative effects on soil animals. Chlorinated hydrocarbons have long-lasting effects on soil fauna due to their poor decomposition. Phosphoric acid esters, carbamates, and pyrethroids have short-term but highly toxic effects.

Green Manuring

The application of leguminous or non-leguminous cover crops as green manure improves the amount of organic matter and biochemical properties of the soil, such as nutrient mineralization, compared to traditional NPK-fertilization (Hwang et al., 2015). Legumes affect the N-availability of the soil, while non-leguminous green manure plants have an effect on the C-availability of the soil (Chavarria et al., 2016). Rhizobium bacteria, which enter into a symbiotic relationship with legume plants, give the elemental nitrogen they fix from the air to the plant, while they take C from the plant and exhibit a common life together. For this reason, leguminous plants contain more N than other green manure plants. The degree of decomposition of green manures after mixing with the soil and the amount of nutrients that will be released afterwards vary depending on the physical (moisture, temperature, structure, structure), chemical (nutrient amount, pH) and biological (biological activity) properties of the soil (Myers et al., 1994). Another important factor affecting the mineralization rate of vegetable waste mixed with the soil is the C/N ratio.

Legume type green manure plants undergo mineralization shortly after mixing with the soil, increasing the amount of useful nitrogen (ammonium and nitrate) in the soil (Figure 1). Legume crops; They are more preferred as green manure plants due to their positive features such as their rapid development, creating a large amount of green parts in a short time, adding organic matter to the soil, bringing free nitrogen of the air to the soil, and at the same time containing high nitrogen in the green parts, contributing to the aeration of the soil by rotting deep and taproots (Tejada et al., 2008).

When green manures are mixed into the soil, they are quickly decomposed by microorganisms at the appropriate moisture level. In systems with reduced or no tillage, waste accumulates on the soil surface and the decomposition process proceeds slowly, similar to in natural ecosystems. Microbial activity is very intense in the part of the vegetative waste layer that is in contact with the moist soil surface. Decomposition continues under this layer, and the waste pile is actively used by soil microorganisms. During decomposition, part of this waste layer is carried by the soil fauna to the lower parts of the soil, where it also begins to actively decompose.

In the decomposition of vegetable waste, the process can take place in aerobic or anaerobic conditions. But in many soils, the aerobic process is of greater importance. Because in aerobic decomposition, the mineralization of organic compounds in vegetable wastes results in the final product, CO2, water and inorganic substances. The decomposition of wastes proceeds with the cooperation of many different organisms. Substrates with a simple structure, which can be assimilated immediately, have a community of microorganisms that feed on each other in competition. More complex and resistant substrates, such as carbohydrate polymers, are initially attacked by a group that breaks down the polymers into simpler components. Then other groups of microorganisms that can use these simple components come into play. In almost all cases, the final stage ends with the assimilation of the decomposition products of different microorganisms, which oxidize some compounds to obtain energy and carbon to form new cell tissues.

Simple compounds in the structure of vegetable wastes are converted into completely new cell components and CO2 within a few days under suitable conditions. For example, glucose is completely metabolized by microorganisms within 1 or 2 days. Amino acids are also immediately used by microorganisms. Meanwhile, the cytoplasmic components of cells that break down or die are easily used by other microorganisms. As the decomposition of organic wastes progresses, substances resistant to decomposition begin to accumulate and reactive aromatic compounds begin to form. Reactive aromatics, such as phenolic compounds, participate in condensation reactions to form new polymeric materials. Some of these new polymers may be even more resistant than the original plant tissues. The pool formed by this newly formed pool of complex carbon materials is extremely resistant to decomposition and forms soil organic matter (TOM). This process, known as humification, goes hand in hand with the microbial decomposition of waste. Only 10-20% of the carbon in raw vegetable wastes entering the soil is added to soil organic matter.

They contain organic compounds such as vegetable residues, free amino acids, organic acids and sugars that are soluble in water and can be used immediately by the vast majority of soil microorganisms. These materials are immediately taken up by microorganisms for use in anabolic (biochemical reactions involving the synthesis of cell components from simpler molecules) and catabolic (biochemical reactions that the cell uses to produce energy) reactions. Water-soluble compounds are often used by bacteria and sugar fungi (such as Mucor and Rhizopus species). These microorganisms, which show rapid development, are zymogen organisms of the soil.

With green manure, a significant amount of protein comes to the soils. As a polymer of amino acids linked by peptide bonds, proteins can decompose immediately in soil. The vast majority of microorganisms hydrolyze proteins into amino acids with protolytic enzymes (protease, peptidase). These products are then either transferred to the cell for further catabolism or used in the synthesis of new proteins.

Proteins ————- > Protease, peptidase               > Peptidlcr, Amino acids

The most common structural polysaccharide in vegetable waste is cellulose. In terms of structure, the cellulose molecule consists of straight chain-shaped glucose units linked together by ß-bonds. Each cellulose molecule can contain up to 10,000 glucose units. The cellulose content of plants increases with age. While this rate is 15% in young plants, it goes up to 50% in old tissues. Cellulose is also an important component of the fungus and algae cell wall. Since cellulose is a polymer that does not dissolve in water and is too large to enter the cell, it must first be broken down into smaller units by extracellular enzymes. Only after this process can it be transferred to the microbial cell. Cellulose is decomposed in the soil by a group of enzymes known as cellulases. After decomposing cellulose into glucose molecules through these enzymes, it can be metabolized in the cell for energy and biomass production.  Soil fungi such as Trichoderma, Aspergillus, Penicillium and Fusarium, and bacteria such as Streptomyces (Actinomycete) and Pseudomonas and Bacillus are important organisms effective in the decomposition of cellulose.

Cellulose ————————– » Cellobiosis                                            > Glucose

(Cellulase enzyme)                          (B-glucosidase enzyme)

Polysaccharides, defined as hemicellulose, are the main plant components that are added to the soil in high amounts at the second level after cellulose and provide an important source of nutrients and energy for microorganisms. They include hemicelluloses, hexose (6-C sugars), pentose (5-C sugars) and uronic acids. They make up about 30% of vegetable residues and usually contain between 50-200 sugar units in their structure. The decomposition of hemicellulose is generally faster than the decomposition of cellulose. Most aerobic and anaerobic microorganisms use hemicellulose for development and new cell synthesis. Hemicelluloses can be decomposed by many groups of microorganisms in the soil.

Lignin is usually the third common compound of vegetable tissues. Young plants may have a lignin content of less than 5%, while mature plants may contain 15% lignin. The main structure of lignin is phenylpropenes. Lignin typically contains between 500-600 phenylpropene. Due to the fact that it contains aromatic rings in its structure, its decomposition in the soil is slower than other tissue components. A significant amount of lignin enters the soils from both roots and above-ground plant tissues. Due to the size, nitrogen-free and complex structure of lignin molecules, the decomposition rate is approximately 3 times higher than cellulose and hemicellulose

It is slow. The microbial group responsible for the decomposition of lignin is Basidiomycets, especially from fungi. However,  they can decompose Streptomycet from actinomycetes and Pseodomonas and Flavobacterium  lignin  from bacteria. Since the first decomposition products of lignin cannot be used immediately by microorganisms, they accumulate in the soil and enter into polymerization reactions again and are effective in the formation of humin substances. Therefore, there is a close relationship between the formation of soil humus and the decomposition and decomposition products of ligninated compounds.

Favorable conditions that accelerate the decomposition of vegetable residues and the reproduction of microorganisms are:

1. Vegetable residues with low lignin content and small size
2. Wastes with an appropriate amount of useful nitrogen or a low C/N ratio
3. Neutral soil pH
4. Proper soil moisture and aeration
5. It is a suitable soil temperature.

Temperature and soil moisture are highly influential factors in the rate of decomposition of vegetable waste. With the increase in temperature from low degrees to 20 °C, the decomposition rate increases. For maximum weathering, the water content of the soil should be about 60% of its water holding capacity. This humidity level provides a good ventilation condition for oxidative events and sufficient humidity for all groups of heterotrophic mycoorganisms that play a more active role in decomposition.

Çengel et al. (2009), in their organic vineyard experiments; They investigated the effects of barley + vetch (A + F), broad beans + vetch (B + F) and farm manure (WG) applications on microbial activity in the soil. As green manure, broad bean + vetch mixture 10 + 4 kg / da; Barley+vetch mixture was applied at 5+6 kg/da and farm manure at 1+6 t/da. It was determined that the most effective application in the increase of the total amount of organic carbon in the soil was A + F, and the most effective application in the increase of humic matter was A + F and B + F applications; In addition, it has been determined that green manures stimulate microbiological activity in the soil more than farm fertilizer.

The effects of green manure on soil physical and biological properties, wheat yield and nitrogen uptake 2 times a year apart were investigated by Abdallahi and N’Dayegamiye (2000). Meadow trirose (Trifolium pratense L.), buckwheat (Fagopyrum esculentum L.), millet (Sorghum sudanensis L.), mustard (Brassica hirta Moench) and rapeseed (Brassica campestris L.) plants were used as green manures. The researchers found that green manure applications statistically increased microbial biomass, alkaline phosphatase and urease activities and N mineralization capacity compared to the control.

Soil microbial biomass and microbial enzymes can respond more quickly to changes in soil management than other variables and are therefore considered early indicators of biological changes (Garcia et al., 2000; Masciandaro et al., 2004). In fact, they also demonstrate the sustainable microbiological activity of the soil (Paul and Clark, 1989). Therefore, the measurement of microbial biomass and enzymatic activities are sensitive indicators of the transformations of vegetable or animal wastes added to the soil.

In a study investigating the effect of Trifolium pratense, L. (TP), Brassica napus, L. (BN) and a mixture of the two used as green manure on the biological properties of the soil; it was determined that all green manures were effective, but TP application showed the highest effect. It was found that TP green manure increased microbial biomass by 79%, dehydrogenase activity by 92%, urease activity by 94%, β-glucosidase activity by 99%, phosphatase activity by 88% and arylsulfatase activity by 96% compared to the control (Tejada et al., 2008).

Stark et al., (2007) determined that after the addition of different green manures to the soil, soil microbial biomass and soil respiration increased in a short time. This increase in soil microbial biomass carbon and soil respiration is due to the mixing of quickly degradable materials into the soil, which stimulates autochthonous microbial activity and enables the entry of exogenous microorganisms into the soil (Blagodatsky et al., 2000). Soil microbial respiration, measured through CO2 production, is a direct indicator of microbial activity and indirectly indicates the level of decomposition of organic material (Tejada et al., 2006).

Soil microorganisms decompose organic substances by secreting various extracellular enzymes. Therefore, after the application of green manures to the soil, the enzymatic activity in the soil is expected to increase. Because the vegetable wastes added to the soil contain enzymes secreted both intracellular and extracellular and stimulate the microbial activity in the soil. However, the decomposition of green manures in field conditions does not only depend on microbial activity in the soil. Other factors affecting decomposition are the C/N ratio, the biochemical structure of the vegetable waste, the level of contact between the soil and the vegetable waste, and soil properties and climatic conditions. According to Tejada and Gonzalez (2006), the C/N ratio of organic waste largely determines the balance between mineralization and immobilization. The C/N ratio is the most decisive parameter indicating the amount of potential N that can be mineralized from a vegetable waste (Chaves et al., 2004). Maiksteniene and Arlauskiene (2004) reported that alfalfa and hybrid tricours (C/N ratios 12 and 10) green manures had higher mineralization rates compared to vetch and oat mixture (C/N ratio 31) and wheat straw (C/N ratio 55). Therefore, increases in microbial biomass-C and enzymatic activity in the soil may vary depending on the type of green manure applied to the soil.

Driver et al. (2014), who examined the changes in urease and dehydrogenase enzyme activity in soils under green manure-corn-wheat rotation; As green manure, they mixed the above-ground and below-ground parts of the broad bean plant with soils at different nitrogen levels. The researchers found that the application of broad beans as winter cover vegetation increased the enzyme activity of the soil compared to the control, and that mixing all parts of the broad beans with the soil was more effective on dehydrogenase and urease enzyme activities.

Khan et al. (2020) investigated the effects of barley (Hordeum vulgare) and downy vetch (Vicia villosa), which they applied as green manure in paddy production, on soil nutrient availability, microbial group, biomass and enzyme activities, and found that green manures significantly increased the composition of the main microbial groups, microbial biomass-C and hydrolase enzyme activity compared to inorganic fertilization. The effect of green manures on microbial groups and enzyme activities has been in different directions. Barley plants had more effect on enzymes related to the C-cycle, while hairy vetch had more effect on enzymes related to the N and P-cycle. This difference was probably due to the difference in the chemical composition of green manures and their mineralization rate, which is controlled by the C/N ratio.

Green manure applications can also change the microbial community composition of the soil. Asghar and Kataoka (2022); They found that the fungal community composition of the soils to which they applied a legume (hairy vetch) and non-legume (Brassica juncea) green manure plant changed compared to the control soil. It has been reported that mixing legumes into the soil as green manure provides a better plant growth due to the amount of useful inorganic nitrogen in the soil, enzymatic activity and increase in fungal biomass.  Studies using Astragalus sincus as a green manure have also found that the paddy plant changes the endophytic bacterial community composition (Zhang et al., 2013; Wang et al., 2022).

RESULT

Green manure applications can directly or indirectly affect the microbial communities in the soil. The direct effect is due to the abundant amount of C and N that comes to the soil with green manure, and the indirect effect is due to the improvement in soil properties. Soil temperature and pH are important factors that influence the microbial composition of soils under different fertilization regimes and crop production systems. Plants, on the other hand, affect the microbial diversity of the soil with their root secretions.

Vegetable wastes mixed with the soil as green manure increase the microorganism population, microbial biomass and enzyme activity in the soil. Legumes, which have a narrow C/N ratio due to the N transferred by Rhizobium bacteria, are decomposed in a short time by heteretrophic bacteria and fungi (microorganisms that use C and organic matter as an energy source) under suitable soil and climatic conditions when mixed with the soil. Plants and also autotrophic bacteria (bacteria that obtain carbon from inorganic C-sources and their energy from the oxidation of inorganic substances) benefit from the inorganic substances produced at the end of the mineralization process. In addition, as a result of the increase in soil microflora caused by green manure applications, there are significant increases in the populations of soil microfauna (protozoa and nematodes) that feed on bacteria and fungi.

As green manure, the effects of leguminous plants and non-leguminous plants on microbial groups and enzyme activity in the soil can occur in different ways. Therefore, there is still a need for research on scientific platforms investigating the synergistic effects of non-leguminous green manures on the microbial community and functions of the soil, as well as their relationship with soil fertility and productivity.

CHAPTER 6

THE IMPORTANCE OF GREEN FERTILIZATION IN FIELD PLANT AGRICULTURE

ENTRANCE

Green manuring is a very old practice used to improve soil productivity and sustainability in many parts of the world. 300 years before Christ, the Greeks buried broad beans (Vicia faba L.) in the ground; It has also been reported that pod and lupine species (Lupinus sp.) were cultivated in the Roman Empire to improve the soil  (Fageria, 2007). In China, it has been reported that about 3000 years ago, plants belonging to the legume family were mixed with the soil before flowering (Açıkgöz, 2021). According to MacRae and Mehuys (1985); In North America, green manuring has been practiced since the 18th century. Practices such as green manure, compost application, crop rotation and intercropping, which were used in various soil fertility programs for developing countries until the early 1960s, decreased with the increase in the use of mineral fertilizers (Fageria, 2002). In recent years, this scenario has changed drastically again due to the high cost of energy and the correspondingly high prices of chemical fertilizers. In addition, ecological and environmental concerns regarding the increasing and indiscriminate use of chemical fertilizers have necessitated the use of organic fertilizers (Ayoub, 1999; Fageria, 2002). In addition, due to the need to develop sustainable agricultural systems, there has been a resurgence of interest in green manure today (Fageria, 2007).

Basically, green manure applied to increase and/or improve soil fertility; It is known to increase the yield of the products that come after it and to improve the product quality in many plants depending on the cultivation system and plant species. In this section, the effects of green manure in field crops, which is one of the important application areas, are emphasized.

EFFECTS OF GREEN FERTILIZATION ON YIELD AND QUALITY OF FIELD PLANTS

Green manure has many benefits such as increasing the amount of nitrogen (N) and organic matter in the soil, improving the structure of the soil, making the plant nutrients in the soil more useful, increasing the yield and quality of the next product, reducing the fertilizer need of the subsequent plant, reducing diseases and pests (Fageria, 2007; Gold et al., 2009; Açıkgöz, 2021).

After green manure applications, there are significant increases in the yield of the planted products and improvements in their quality.

Conducted by Özyazıcı and Manga (2000) in the irrigated conditions of the Çarşamba Plain, large vetch (Vicia narbonensis L.), common vetch (Vicia sativa L.), Anatolian trifolium (Trifolium resupinatum L.), damson (Lathyrus sativus L.), fodder peas (Pisum arvense L.) and white lupine (Lupinus albus L.)’ In a study in which corn + green manure + corn and corn + green manure + sunflower crop rotation systems were discussed. As a result of the research; It was determined that the highest grain yields in the main summer crop corn and sunflower plants were obtained from green manure applications in which all parts of big vetch and common vetch were mixed with the soil, and green manure applications provided yield increases of 51.7% and 50.0% in corn and 36.8% and 36.4% in sunflower, respectively. In the study, it was also reported that some parameters and quality characteristics that affect yield such as plant height, thousand grain weight and crude protein ratio in both plants, cob length and number of grains on the cob in corn, table diameter and crude oil ratio in sunflower were positively affected by green manure applications.

In a study initiated by Mureithi et al. (2005) in Central Kenya in 1997 and lasting for 3 years, the effects of the inclusion of legumes as green manure in the maize (Zea mays L.) production system were evaluated. The legumes included in the study  were Mucuna pruriens L. and Crotalaria ochroleuca, which were planted between the corn rows two weeks after corn planting  . As a result of the research, it was found that legume applications increased the corn grain yield, which was approximately 1.0 t/ha in terms of control, to an average of 1.6 t/ha.

In a study conducted by Zahir et al. (2011) in Pakistan; mung bean used as a green manure plant (Vigna radiata), black-eyed peas (Vigna unguiculata), soybeans (Glycine max), sesbanya (Sesbania rostrata), pigeon peas (Cajanus cajan) and gum beans (Cyamopsis tetragonoloba) yields of wheat, straw and N were significantly higher than that of three-year fallow paddy-wheat rotation. According to the researchers, compared to fallow, the average improvement achieved as a result of green manure; grain yield of wheat was 18.1%, straw yield was 18.4%, and total N intake was 59.7% in grain and straw of wheat. Also in the research; 27.5% in grain yield, 24.5% in hay yield and % in N uptake in wheat       The biggest gain of 82.8 is the green of sesbanya.

It is explained that it is obtained from fertilization.

Karakurt et al. (2016) conducted a study in barren conditions in Ankara; They examined the effect of green manure (hairy vetch, triticale, safflower, stubble+stalk addition, vetch+triticale mixture, winter lentils, common vetch, summer lentils), fallow (traditional fallow-end of March) and late fallow (end of June) practices on the yield and quality of durum wheat. The researchers found that durum wheat grown after downy vetch yielded the best results; This was followed by widespread vetch and traditional fallow practices.

In a study conducted in Greece, the effect of green manure applications on the yield and yield characteristics of corn hybrids was determined and meadow trirose (Trifolium pratense L.) and white trirose (T. repens L.) were used as green manure plants. As a result of the research; It has been reported that plants used as green manure increase corn yield by up to 5-6% and that both meadow tripod and white tripod green manure will be beneficial for corn productivity in Greek conditions (Kanatas et al., 2020).

To show the effect of green manure applications on subsequent wheat, corn and potato yields, Ma et al. (2021); They collected the research on the use of green manure in the production of these crops; They evaluated 66 studies for wheat, 30 for corn and 8 for potatoes. In these researches, as a green manure plant; soybean (Glycine max), mung bean (Phaseolus aureus), alfalfa (Medicago sativa), yellow thacila (Melilotus officinalis), hairy vetch (Vicia villosa), beans (Phaseolus vulgaris), peas (Pisum sativum), crotalia (Crotalaria juncea), rapeseed (Brassica napus), February orchid (Orychophragmus violaceus) and Italian grass (Lolium multiflorum). As a result of the analysis, the researchers; corn yield, all green manure applications; Wheat yield, on the other hand, is only green manure plants belonging to the legume family; They also found that only green manure plants that do not belong to the legume family increased potato yield.

In some other studies carried out, in general, the application of green manures; by improving the physico-chemical and biological properties of soils and the amount of macro and micronutrients, maize (Tejada et al., 2008), paddy (Shah et al., 2011; Gao et al., 2016; Wang et al., 2022), sesame (Jalilian et al., 2022a), it has been reported to increase yields in some important field crops and improve the quality parameters of some products.

Nitrogen is an important macronutrient for plant growth and is an important part of proteins, protoplasm, enzymes and biological catalytic agents that accelerate life processes; building blocks of nucleoproteins, amino acids, amines, sugar acids, polypeptides and organic compounds in plants; It is the component of chlorophyll, which plays an important role in the process of photosynthesis. In green manure applications; The improvement in the growth, yield and quality of plants is due to the above-mentioned metabolic and physiological functions of nitrogen added to the soil by green manure plants. In addition; The decomposition of green manure is the process of restoring plant nutrients to the field. The nutrient cycle with plant residues also increases microbial activity in the soil. All these processes also have positive effects on product efficiency.

The increase in yield in field crops grown after green manure is closely related to the plants used as green manure and the amount of biomass of these plants. The high amount of biomass buried in the soil ensures that more organic matter is formed due to the decomposition of the soil and that plant nutrients become favorable. This plays a role in improving the yield and quality of naturally planted crops.

In the green manure application made in Çarşamba Plain, the green manure plant that produced the most biomass was the big vetch, and higher grain yield was obtained in the corn and sunflower plants planted after the big vetch buried in the soil (Özyazıcı and Manga, 2000). Liu et al. (2009) reported that changing or controlling the amount and type of organic additives can increase the nutrient content and paddy yield of paddy soil. Ross et al. (2009), in their study conducted in two locations with fertile and infertile soils to determine the effects of some plants used as green manure in Canada on barley yield; As a green manure plant, long-toothed trirose (Trifolium michelianum Savi), Alexandrian trirose (T. alexandrinum L.), red trirose (T. incarnatum L.), Persian trirose (T. resupinatum L.), perennial trirose species such as hybrid trirose (T. hybridum L.), meadow trirose (T. pratense L.) and white trirose (T. repens L.)’ and rye (Secale cereale L.) as a wheat plant  . Researchers have reported that the biomass yield of annual tricole species is higher than that of perennials, with the highest yield being obtained from the Alexandrian trirose. In the study, it was also found that the effect of green manures on the amount of N in the soil and barley yield was less in fertile soils; In the experiment in the location with infertile soils, it was reported that all trirose species except the long-toothed tripod type increased the yield of barley and that the grain yield in barley planted after perennial tripods was higher than that planted after one-year trigules. Bilalis et al. (2012) used common vetch (Vicia sativa), fodder pod (Vicia faba) and pea (Pisum sativum) as green manure plants before corn; that fodder pods and common vetch create higher biomass than peas and that the lowest yield is obtained when peas are used as green manure; They reported that common vetch is the most suitable species for the use of green manure.

A study has shown that green manure types and dose (5, 7.5 and 10 t/ha) increase corn’s leaf area, stem diameter, cob length and grain yield. As a result of this research, in which mince beans, peanuts and Centrosema pubescens plants were used as green manure; the highest nutrient intake [7.68% N, 0.39% phosphorus (P), 0.09% potassium (K)] and corn production (6.44 t/ha)  were obtained from C. pubescens green manure application applied 10 tons per hectare  (Idham et al., 2021).

 In a study in which three different application levels (0, 6.3 and 12.6 t/ha) of Leucaena leucocephala green manure plant were discussed; There are significant differences between green manure doses in terms of dry matter (KM), crude protein (HP), ether extract, ash, insoluble fiber (ADF) in acid detergent, fiber insoluble in neutral detergent (NDF), calcium (Ca), K, P, iron (Fe), copper (Cu) and zinc (Zn) ratios in corn varieties,  It was reported that the highest KM, ether extract, NDF, ADF, Ca, K, P and Cu ratios were obtained from 12.6 t/ha, and the highest HP, ash and Zn ratios were obtained from 6.3 t/ha green manure application level (Okukenu et al., 2022).

With green manuring, a significant amount of N is added to the soil. Although this amount varies according to the green manure plant used; Legumes, which have biological N fixation capacity, reach much more important dimensions with green manure plants. For this reason, green manures and/or green manure meet some or even all of the nitrogen needs of the crops that come after it; in this respect, green manure makes important contributions to reducing the use of nitrogen fertilizers in field crops.

In this sense, Fageria (2007) reported that green manure alone is not sufficient for maximum yield, so it is best practice to use green manure together with chemical fertilizers, so that the amount of chemical fertilizer application and the risk of environmental pollution can be reduced, and sustainability can increase in plant production systems.

Aygün (2001), in a study he conducted in Menemen ecological conditions, used common vetch, broad beans, fodder peas, barley, fodder rapeseed and common vetch + barley mixture as green manure plants; In addition, it has experimented with practices such as cleaning cotton stubble and mixing it with the soil with nitrogen fertilization used in traditional cotton cultivation and removing the stalks out of the field after the cotton harvest. Searching; It has been reported that green manure of common vetch, broad beans and fodder peas and nitrogen commercial fertilizer application positively affect the yield of cotton wool. Turgut et al. (2005) investigated the effect of green manure and nitrogen fertilization on the yield and some yield characteristics of sugar corn in their study under Bursa conditions. Fodder peas (Pisum sativum L.), common vetch (Vicia sativa L.) and pods (Vicia faba L.), while in nitrogen fertilizer 0,                                              Doses of 12, 24 and 36 kg/da

they have tried. Researchers, as a result of the experiment; They stated that nitrogen fertilizer to be used together with green manure can be reduced up to 12 kg per decare.

In another study conducted in the ecological conditions of Bursa, common vetch (Vicia sativa L.) bred; different doses of N (0, 7.5, 15.0,      22.5,      30.0 and 37.5 kg N/da)

has been trained. According to the results of the study in which wheat stubble was used as a control; It has been stated that a dose of 15 kg N/da to be applied to corn planted after common vetch grown for green manure will be sufficient, and as the N dose increases in corn planted for wheat stubble, grain yield increases up to 30 kg N/da dose (Uzun et al., 2005).

In another study, Özyazıcı et al. (2009); They aimed to identify the possibilities of green manuring in the conditions of the Wednesday Plain, reducing the use of chemical fertilizers in corn and wheat grown after it. Green manure + corn + wheat rotation system is applied and fodder pod (Vicia faba L.) is used as a green manure plant  . In the study, two different green manure applications were made, in which the fodder pod was completely buried in the soil and the remaining stubble was buried in the soil after the grass was mowed and removed; After both applications, corn and wheat were grown alternately and 0, 6, 12, 18 kg N/da nitrogen was applied for corn and 0, 5, 10, 15 kg N/da for wheat. As a result of the research, it was determined that fodder pods can be grown as green manure in the winter interim period under the conditions of Çarşamba Plain; It has been reported that it will be sufficient to give 12 kg/da N to corn grown for green manure and 10 kg/da N to wheat grown after corn.

In a study conducted by Islam et al. (2019), the effect of green manure and nitrogen fertilizer on yield and some properties of paddy was examined. In the study, two green manure plants (Sesbania aculata and Crotalaria juncea) belonging to the legume family and twelve different applications [Control (no green manure + no chemical fertilizer), Sesbania aculeata + N0, Sesbania aculeata + N15, Sesbania aculeata + N30, Sesbania aculeata + N45, Sesbania aculeata + N60, Crotalaria juncea + N0, Crotalaria juncea + N15, Crotalaria juncea + N30, Crotalaria juncea + N45, Crotalaria juncea + N60 and N60]. In the study, the paddy grain yield obtained as a result of combining green manure with nitrogen fertilizer was higher than the control and N60 applications. According to the results of the research; It has been predicted that the continuous use of chemical fertilizers may lead to yield losses in paddy and this situation can be avoided by applying green manure and nitrogen fertilizer together.

Zhou et al. (2020) conducted another study in which green manure was tried together with chemical fertilizers in Southern China. In this study; applications of non-fertilizer, chemical fertilizer, chemical fertilizer + green manure, chemical fertilizer + paddy straw, chemical fertilizer + green manure + paddy straw were examined; Astragalus sinicus L. was also used as a green manure plant. As a result of the study; It has been reported that the lowest paddy yield is obtained from non-fertilizer plots and the highest yield is obtained from chemical fertilizer + green manure + paddy straw application.

In a study conducted in Pakistani conditions, it was investigated how green manure and N use affect wheat yield. Five applications [green manure; green manure + 25% N (30 kg N/ha); green manure + 50% N (60 kg N/ha); green manure + 75% N (90 kg N/ha); green manure + 100% N (120 kg N/ha)] were carried out in the study.  As a result of this research, wheat was planted after sesbania (Sesbania aculeata), which is used as a green manure plant; It has been reported that when 75% and 100% N are applied to wheat after green manure, the values increase in all examined characteristics except plant height and chlorophyll content and more wheat grain yield is obtained. Also in the research; It has been reported that green manure alone without the addition of nitrogen fertilizer cannot meet the N requirement of wheat plants (Muhammad et al., 2022).

In some studies, the effects of barn manure used together with green manure on some field crops have been examined. For example; Akkaya and Kara (2018) grew summer wheat by adding barn manure to vetch and buckwheat green manure in Isparta ecological conditions and examined yield, some yield characteristics and protein contents. In this study, traditional fertilization (control), barn manure, vetch green manure, buckwheat green manure, vetch green manure + barn manure and buckwheat green manure + barn manure applications were tried; The highest grain yield and protein ratio in wheat were obtained from traditional fertilizer application, and the thousand grain weight was obtained from vetch green manure + barn manure application. When green manure and barn manure applications were compared, the highest values were found in vetch green manure + barn manure applications. The researchers reported that under sustainable agricultural conditions, vetch green manure + barn manure application can be an alternative in terms of acceptable yield amount and protein ratio. In another study conducted in Iran, the effect of animal manure and green manure on sesame yield was investigated. In the study, animal manure (0, 10 and 20 t/ha) and green manure (without green manure, Alexandrian trirose, fenugreek and hairy vetch) were considered as factors. Based on the data obtained as a result of the research; It has been suggested to use 20 t/ha of animal manure along with fenugreek green manure to increase sesame yield (Jalilian et al., 2022b).

RESULT

Green manure is a practice that has been known since ancient times and has increased in importance in recent years. With green fertilization to be made using suitable plants, an increase in yield is achieved in the next plant, the amount of nutrients in the soil increases, and the sustainability of soil fertility is realized. Especially in the cultivation of products that use a lot of nitrogen fertilizers, the application of chemical fertilizers and green fertilizers together will reduce both the amount of chemical fertilizers to be used and the risk of environmental pollution. In particular, the cultivation of forage crops belonging to the annual legume family as green manure plants as an intermediate product or second product by entering the sowing rotation before the main product will make the expected benefits of green manure more evident and noticeable in the long run.

CHAPTER 7

THE IMPORTANCE OF GREEN FERTILIZATION IN HORTICULTURAL AGRICULTURE

ENTRANCE

With its suitable ecological and geographical conditions, its location on trade routes from past to present, and its Anatolian geography, which is home to civilizations with different cultures, Turkey has an important production potential in terms of viticulture with fruit and vegetable species within the scope of horticulture in the agricultural sense. Turkey, which covers both the Near East and the Mediterranean basin among the plant gene centers available in the world, is the center of origin of many fruit, vegetable species and populations cultivated today (Harlan, 1951; Balkaya and Yanmaz, 2001; Tan, 2010). Turkey, which is located at the intersection of continents, has many climates and microclimates thanks to its structure consisting of different ecosystems. As a natural consequence of this wide variation in climate, a large number of species and varieties of fruits, vegetables and ornamental plants are grown. Biodiversity supported by ecological conditions makes Turkey an important geography in terms of endemic plant species. Biodiversity, rich climatic and geographical conditions enable the development of agriculture and agriculture-based industry, an increase in the amount of exports and the sustainability of agriculture.

All other living things, especially humans, have to live their lives depending on natural resources. One of these natural resources is the “soil” from which all living things provide their food. The importance of sustainability naturally comes to the fore in the protection and use of agricultural lands, which are limited to resources and the need for protection are non-renewable. In addition, it is important for sustainable agriculture to determine the effects of different inputs on plant growth, yield and food quality in order to increase plant yield. The sustainability of soil resources is ensured by determining and monitoring soil quality. The “sustainability” of the world we live in directly depends on the sustainability of the soil, where all food is provided by plants.

In the world, the cultivation of species entering the field of horticulture, the production area and the total amount of production have high potential; In addition, it contains cultivated plants that have an important place in human nutrition and health. When the production data of the plant species in horticulture in Turkey in 2021 are examined; vegetable species were 31.8 million tons, fruit species were 24.9 million tons, and grape production (vineyard) was 3.67 million tons (Anonymous, 2022).

Vegetables, which are among the types of horticultural crops, are among the most cultivated plant groups in Turkey. Turkey ranks fourth after China, India and the United States in terms of vegetable production. While more than 50 types of vegetables are grown in Turkey; In recent years, with consumer demands, developing market conditions, the introduction of new species and the developing tourism sector, diversity in consumption has increased and different types of vegetables have started to be grown. In addition, with the ongoing developments in gastronomy, new (exotic) vegetable species that have enriched the way of consumption, miniature vegetables, germinated seeds, sprouts and edible flowers, the richness of presentation has increased as well as the richness of species.

Turkey has an important position among the countries of the world in terms of the number and variety of vegetable species grown. Vegetable production in Turkey is carried out in the form of open field conditions or greenhouse vegetable cultivation depending on different ecological conditions. Open vegetable cultivation is carried out for table and industrial vegetable growing, and greenhouse cultivation is carried out for table production. A significant part of the vegetable species subject to export consists of species that have the chance to be grown under cover where the necessary quality and product standardization can be achieved. Although greenhouse cultivation, which allows vegetable cultivation outside the production season, gives Turkey the chance to export throughout the year, the share of exports in total vegetable production remains low. The fact that fruit growing, which is among the important agricultural products of Turkish agriculture, provides a higher income compared to many other agricultural production branches, and the increase in the export of fresh fruits and processed products by evaluating them in different ways allows the expansion of production areas. On the other hand, considering the characteristics of fruit growing enterprises established in recent years, the implementation of the intensive business model is successful with the use of more information and modern technologies. A similar structure is observed in the field of viticulture; Grape cultivation has an important place in Turkey’s herbal product pattern in terms of production area and production amount. Viticulture in Turkey also has an old and deep-rooted culture; Grapes are one of the common cultivated plants in the world and in Turkey because they are not too picky in terms of climate and soil and have alternative evaluation opportunities. While Turkey ranks 6th in world grape production, grapes have high biodiversity and local varieties (Semerci et al., 2015).

In Turkey, which has an extremely important potential in horticultural agriculture, soil characteristics are one of the factors limiting yield and quality, as in other agricultural products. A number of cultural activities such as excessive use of fertilizers, improper tillage, unconscious irrigation management also play a role in not obtaining the desired quality yield. For this reason, in today’s world, where food safety is discussed in much more serious dimensions in parallel with the increasing human population, it is important to immediately implement sustainable agricultural approaches to increase the yield and quality of horticultural products. In this sense, ecological practices such as green manure, which increases soil fertility, improves the physical, chemical and biological properties of soils and makes significant contributions to the yield and quality of products, should be given much more place in horticultural agriculture. In this section, the importance of green manure in horticulture is examined.

GREEN FERTILIZATION IN VEGETABLE GROWING

When the production amounts of annual plant species in Turkey are examined, it is seen that a large part of these species continue in the form of monoculture agriculture without scientific crop rotation. This situation;

 s Disruption of the nutrient cycle in the soil,

 Excessive use of inputs in order to maintain soil fertility and thus pollution of soils,

 s Increase in disease and pest populations,

J Negative impact on water use efficiency and water holding capacity of soils,

J As  a result of reasons such as the accumulation of pollutants in the soil of some plant species, it causes the disappearance of ecosystem-based agricultural sustainability.

Considering the practical applications of crop production in Turkey, it is seen that the organic matter content of agricultural soils is not at the desired level. Organic fertilizers or composted vegetable wastes obtained from different sources make important contributions to increasing the amount of soil organic matter, which is gradually decreasing, as well as meeting the nutrients needed by plants. However, fertilizers of organic origin are not available in sufficient quantities; Since the existing ones cannot be stored in appropriate ways and applied to the soil, they cause environmental pollution caused by agriculture.

In sustainable agricultural systems, crop rotation and green manure in sustainable use of soil significantly affect the performance, yield and quality characteristics of agricultural production, and well-planned crop rotation has a direct effect on soil fertility (Schönhart et al., 2011). Green manuring in general; It is called bringing green manure plants, which have been grown on-site or grown elsewhere to enrich the soil, under the ground using different tillage methods while the plants are still green in a certain period of their development. Plants grown only for this purpose are called green manure plants.

Especially in places where barn manure is scarce, the organic matter content of the soil is significantly increased by green manure (Anaç and Okur, 1996; Pitter and Ryser, 1999). It is reported that green manure, especially with vetch, gives better results than other green manure plants due to the fact that it increases the organic matter of the soil in green manure (Parton et al., 1987; Ryan, 1998; Whitbread et al., 2000; Katsvairo et al., 2002; Aslan et al., 2013). The use of leguminous vegetables as green manure in vegetable cultivation increases soil health and fertility and sustainability (Dinnes et al., 2002; Fageria and Baligar, 2005). Cultivation of legume species as the main product in vegetable production or evaluation as green manure plants, through the breakdown of plant wastes in the soil; It is reported to increase organic acids, amino acids, sugars, vitamins and mucilage in the soil (Shukla et al., 2011). The increase in these compounds in the soil, especially in vegetable species whose fruits are eaten; It positively affects plant development, photosynthesis activity and taste and aroma components of the consumed parts. While beans, cowpeas and broad beans, which are considered as vegetables in Turkey, are grown in all regions due to their high economic potential, these species can be grown with regular soil cultivation because they are anchor plants (who like soil air).

Global climate change (such as temperature increase, insufficient water) affects Turkey more and more every day as it affects the world. The fact that cowpea has been proven to be better in terms of heat and drought tolerance than other edible legumes in semi-arid and tropical regions of the world increases the ecological importance of this species as well as its economic importance. Therefore, cowpea is among the suitable legume species in hot climatic conditions (Singh et al., 1997; Hall et al., 2003; Hall, 2004). In addition to the use of cowpea as a green manure in the temperate climate zone, it provides higher biomass and bioavailability in arid areas compared to other legume species. On the other hand, the fact that it can be grown in waterless conditions, its resistance to stress factors, the genotypes that develop in a diffuse way on the soil surface, providing an advantage in weed control by creating high biomass and reducing water loss will also highlight the breeding of varieties that will only be used as green manure in the coming years.

Different sustainable agricultural practices, such as rotation and green manure, are recommended to prevent pollution of water resources and loss of nitrogen (N). Since green manure plants continue to increase bacterial activity in the upper layer thanks to the shade annealing they create by covering the upper surface of the soil, the structure of the soil becomes suitable for plant growth and tillage is extremely easy. Plants used in green manure are processed together with weeds and mixed with the soil during the period when weeds will be controlled. In subsequent versions, they are completely destroyed. If green manure is left as a thick layer of mulch on the soil surface, weed germination is still prevented (Warman, 1980; Açıkgöz, 1995; Pettygrove and Williams, 1997; Sullivan, 2003; Anonymous, 2013).

Five different leguminous plants (Canavalia ensiformis L., Mucuna pruriens L., Crotalaria ochroleuca L. cv. Rongai, Glycine max L.) were compared in terms of plant N fixation, water consumption, improvement of N and phosphorus (P) in the soil and its effect on subsequent plants in the co-cultivation of beans and corn. It was determined that C. ensiformis, the plant species that produced the highest biome (9.84 mg/ha) and fixed nitrogen in the mixed cultivation of corn and beans, was also the most effective in the extraction of nitrate in the soil and provided the most nitrogen to the plant that came after it. In maize, the best plant growth and grain yield  were obtained from C. ensiformis, while the highest bean plant biome and grain yield were obtained from soybeans (Wortmann et al., 2000). Beşirli et al. (2003) report that 49.4% higher yield values were achieved in green manure applications compared to the plots without application in tomatoes and spinach.

Plants used as green manure allow the vegetative development of the plant to increase the effective root depth. Green manure applications on plant roots with piles and fringe roots have been shown to have a positive effect on carrots, cabbage, onions and lettuce. With the increase in root depth, the amount of N removed from the soil by carrot and cabbage, which form deep roots, increased and was determined from the highest (46 kg/da) winter legume plots, and 24 kg/da N and winter legumes and rye (7 kg/da N) plots in carrots. The N amounts taken from the other two superficial vegetables (onions and lettuce) were determined as 23.9 and 15 kg/da, respectively (Thorup-Kristensen, 2006).

In broccoli cultivation, from the application of meadow trirose (Trifolium pratense L.) and alfalfa (Medicago sativa L.) as green manure; It was  determined that broccoli yield, the N content of broccoli crowns and the upable N content in the soil increased with the application of both green manures. The results obtained reveal that vegetables can be fertilized with organic material by using meadow trirose and clover green manure plants; It is also reported that care should be taken not to increase the amount of nitrate in the consumed parts due to the enrichment of the amount of N in the soil by green manure plants (Theriault et al., 2009).

It has been determined that pre-plant applications, which are summer vegetables such as tomatoes and zucchini grown after different pre-plant and/or fertilizer applications, have limited effect on yield and quality in both tomatoes and zucchini, while pre-plant-fertilizer combinations have a positive effect on yield in tomatoes (Aslan et al., 2013).

Omar (2013) reported that the effects of different green manure plants (broad beans, cowpea, vetch, corn, beans) on yield and quality characteristics in autumn organic lettuce cultivation vary according to green manure plant species. The researcher found that while the effects of green manure plants on plant height, leaf width, stem length, stem diameter, stem weight and root weight in lettuce statistically vary; It reports that its effect on plant diameter, leaf height and root height does not make a statistically significant difference. In lettuce production in the spring period in the same area, plant height, plant diameter, leaf length, leaf width, root length, stem length, stem diameter, stem weight and root weight values are statistically important

has been found. Among the parcels where green manure is applied; The highest values were obtained from the plot where beans were applied in plant height, root height, stem diameter, stem weight and root weight. Plant diameter and stem length, cowpea application; Leaf length and leaf width were obtained from the parcels where vetch was applied.

Yılmaz and Şahin (2014), in their study on the effect of legume plant used as green manure plant on the nutrition and yield of broccoli, it was determined that there were significant increases in crown weights, crown diameter, plant height, number of main leaves and total yields of broccoli plants grown by applying green manure compared to the control application without green manure. In the same study, it was determined that green manure application caused significant increases in the amount of soil N and organic matter in soil samples. The researchers stated that the increase in the yield and quality of broccoli was the result of green manure applications increasing the total amount of N and organic matter in the soil, reducing soil pH and increasing microorganism activities; In particular, they emphasized that green manure with legume plants should be given importance.

In order to determine the effectiveness of green manure application in summer zucchini, 5 green manure plants (common vetch, pea, broad bean, big vetch) were considered and the effect of the applications on yield and quality characteristics was evaluated. While the highest yield increase was obtained from pea green manure, a yield increase of 42.3% was achieved with this application compared to control applications. In the application of peas, where the plant height increased significantly, the N, potassium (K), copper (Cu) and iron (Fe) content of the plant increased compared to other applications. In addition, when the fruit quality characteristics of the applications were examined, it was seen that the green manure application increased the amount of dry matter compared to the control application (Ceylan et al., 2016).

In the comparison of the use of mineral fertilizer (NPK, 15:15:15) in okra with Carica papaya L., Azadirachta indica leaves, Moringa oleifera Lam. and Prosopis africana Guill., Perr. & A. Rich, in the comparison of the use of leaves as green manure, some soil properties were positively affected in the areas where green manure plants were applied, while the effect of these applications on yield and plant growth was higher than in the control groups. has been high.  It was observed that the yield and development of okra in the soils applied to Prosopis africana provided better results than mineral fertilizer and other green manure applications, and the yield increased by 53-214%. When the effect of green manure and mineral fertilizer applications on the biochemical content of the consumed parts of okra was examined  , the highest levels of K, calcium (Ca), Fe, zinc (Zn), Cu and C vitamins were obtained from Moringa oleifera green manure application (Adekiya et al., 2017)

In cultivation, which is generally done with annual vegetable species, green manure applications can be included in the rotation plan. For this purpose; Before starting vegetable cultivation as the main plant, green manure plants can be grown as a pre-plant for one or two growing periods; Generally, plant species in the Brassicacea family are preferred as green manure plants. In some conditions where the production plan is suitable, green manure plants can be grown twice in the same year instead of the mother plant. Rye planted especially in the autumn months is mixed under the ground in the early spring period, and then pod or corn plants are grown immediately after and two green manure plants are grown in a year. In regions with a temperate climate, after the production of summer vegetable species, the cultivation of many Brassicaceae family species in autumn and winter is  terminated by mixing these plants produced for green manure with the soil in spring. The legume of the plants selected for this purpose has other benefits besides the fact that the free nitrogen of the air binds to the soil. Legume crops; Due to its shading effects and loose root systems, it increases the organic matter and structure of the soil, prevents the soil from drying out too much, and ensures the preservation of the soil structure. Plant species with high vegetative growth help control erosion and contribute to the improvement of soil structure. In addition, it prevents cations such as K, Ca and magnesium (Mg) from being washed away in the soil, and is useful in the fight against weeds, diseases and pests (Ceylan, 1994).

It has been shown that barley plant root secretions promote soil dispersion around the rhizosphere, whereas corn plant root secretions promote aggregation, which positively affects soil sturdiness (Naveed et al., 2017). Candido et al. (2002) reported that broccoli, which they used as a pre-plant in the production of organic melons in areas where organic vegetables were produced in Southern Italy, increased the organic matter content of the soil and had positive effects on the quality characteristics of the melon.

Baldwin (2011) stated that rotation in crop production is more beneficial when combined with some practices such as fertilization, cover crop cultivation, green manure and short grazing balance. Studies have shown that brown mustard, which is used as a green manure plant, stores some heavy metals, especially lead, in the soil and removes them from the soil. This method, in which brown mustard is used, has started to be preferred today because it is very easy to apply and relatively cheap for the removal of heavy metals in the soil. In addition, it is reported that soil pollution is reduced and soil erosion is prevented with this application

While the potential to grow vegetables throughout the year is effectively evaluated by the producers in greenhouse cultivation, the protection and development of productivity can only be met with the increasing need for inputs. In addition to the above-ground parts of the plants used in green manure in vegetable cultivation, the amount of organic matter left to the soil with root residues also varies according to the plant species grown. Vegetables remove a high amount of nutrients from the soil from the unit area and can be grown 2-3 times in a year under suitable ecological conditions; This prevents the plant groups that come after them from feeding on the nutrients present in the soil. Some factors should be considered in the crop rotation to be made considering green manure. In particular, species in the same family should not be grown consecutively; As a matter of fact, plant species in the same family generally develop by taking the same nutrients from the soil and cause the soil to become poor in terms of certain nutrients. In addition, some plant species cause the accumulation of soil pollutants depending on their own development structure during the growing periods. This situation results in a negative effect on the development of the species to be grown as the mother plant after the pre-plant grown as green manure. On the other hand, since the susceptibility of species in the same family to diseases and pests may be similar, it would be more beneficial to choose the green manure plant and the main crop plant species from different families.

The use of green manure and ground covers under cover increases the amount of activated carbon in the autumn period; In addition, it allows earlier vegetable cultivation. The ability of farm manure applications to increase soil salinity (Edmeades, 2003) limits the cultivation of many vegetable species, especially those that are sensitive to salt. Ensuring the stability of soil pH with green manuring facilitates the greenhouse cultivation of vegetable species that are sensitive to salinity. Rudisill et al. (2015) revealed that when chicken manure or legumes are used as green manure, total yield and soil quality characteristics of sweet pepper give better results than mineral fertilizer applications.

Caliskan et al. (2014) examined the effect of green manure, farm manure and combinations of these two fertilizers on lettuce cultivation; They report that vetch applied as green manure increases nitrogen uptake in lettuce, increases soil organic matter content, plant growth and yield. In addition, in the same study, it was emphasized that there was no difference between the applications in terms of organic and conventional cultivation in terms of nutritional content of lettuce leaves, especially vitamin C; The most significant effect on growth and yield was observed when green manure was applied to the soil; When green manure was applied together with farm manure, lettuce yield increased. In addition, lettuces grown in green manure and farm manure applications showed higher mineral content than lettuces grown in the conventional production system.

GREEN FERTILIZATION IN FRUIT AND VINEYARD AREAS

While green manure practices in plant product cultivation vary according to the single and perennial nature of the cultivated plant, in vegetable cultivation, green manure plants are included in the rotation program depending on the production planning. In orchards and vineyards established with perennial plant species, green manure plants should be preferred in the areas between the rows. Cultural practices such as the vegetation cycle of the plant species grown in orchards and vineyards, annual maintenance processes are carried out by taking into account the growing conditions of the green manure plant, taking into account the harvest and ecological conditions. In order to protect and improve the physical and chemical structure of the soil, green manure applications are carried out between rows throughout the year. As green manure plants; legumes (alfalfa, meadow trefoil, stone clover, soybean, fodder peas, fodder cowpea, red rove, hairy vetch, Hungarian vetch, hairy-fruited vetch, big vetch, common vetch, peas, damson, lupine, Alexandrian trirose, white trirose), wheat (rye, oats, barley, millet, wheat, grass, Sudanese grass, silage corn) and plants from other families (mustard, rapeseed, radish, poppy, safflower, turnip) are used as lean or mixed.

In the cultivation of perennial plant species such as fruit and vineyard plantations, green manure plants that do not grow too tall, which provide a high amount of nutrients to the soil, should be preferred. In such plantations, Legume forage crops retain free nitrogen in the soil with N-binding bacteria in their roots. Thus, at least 8-13 kg of pure nitrogen is saved per decare. Green manure crops grown on fruit and vineyard plantations reduce erosion, moisture loss and increase yields as they cover the soil surface. It improves the physical structure of the soil, increases its aeration, water retention, capacity and biological activity. Since it is grown for the winter, it does not cause a water deficit in winter and early spring, when rainfall is abundant. It increases the amount of carbon sequestered in the soil. During the flowering period, the amount of organic matter in the soil increases by ploughing and mixing with the soil. Flowering, which is found in the depths of the soil, makes important plant nutrients such as P and K, which increase fruit set and fruit quality, useful for plants. It prevents weed growth and since it can be used as a fodder plant, the most preferred cover crop is legume forage crops.

In organic apple cultivation; The effects of farm manure, seaweed and green manure plants and their different combinations were examined and it was seen that the applied factors significantly affected the plant growth characteristics examined. In addition to farm manure, which is an important food source in organic fruit cultivation, it has been determined that green manure and seaweed applications positively affect the morphological development of the plant (Atasay et al., 2011).

Combinations created with farm manure, green manure, humic acid, organic foliar fertilizer in organic and conventional cultivation of apricot, which is among the important fruit species of Turkey and has a high export volume, were compared with conventional cultivation in terms of yield and pomological properties. 15-20% higher efficiency was obtained from conventional application than organic plant nutrition applications. Of the organic applications (organic fertilizer + sheep manure + green manure), 83.09 kg/tree and 0.16 kg/cm2 gave the best results, while the lowest yield was determined in organic fertilizer + green manure application. In the evaluation made in terms of fruit quality characteristics; In the statistical evaluation for fruit width, fruit height, fruit height, fruit weight and acidity parameters, the best results were obtained from organic applications (Atay et al., 2011).

It is reported that mineral fertilizer and additional farm or green manure applications in citrus cultivation have a positive effect on plant growth characteristics. It has been observed that the applications of farm or green manure together with the application of mineral fertilizers provide the same amount of yield by 15-30% less mineral fertilizer used. In the production of these combinations, mineral

% of fertilizer         Sustainable nitrogen management by saving 30%

strategy (Zhou et al., 2022).

In walnut cultivation, different green manure plants (Orychophragmus violaceus L., Vicia villosa Roth. and Vulpia myuros L.); chemical structure of soil, enzyme activity, soil microbial biome and microbial structure, and its effect on vegetative growth of trees were examined; tree height, crown width, crown height  were obtained from the areas fertilized with the highest Vicia villosa Roth. Orychophragmus violaceus L., and Vulpia myuros L. were followed by the treated areas, while the lowest growth parameters were obtained from the areas where green manure was not applied (Dong et al., 2021).

The effect of farm manure, green manure and mineral fertilizer combinations on plant nutrient balance and productivity in mango cultivation was evaluated; The results obtained indicate that the combined application of mineral fertilizer containing NPK and farm manure or green manure will ensure the sustainability of mango cultivation in terms of yield and fruit quality characteristics (Kumar et al., 2017).

In Antalya conditions, mineral fertilizer application in conventional production in altıntop cultivation and combinations of olive cake compost and green manure in organic production were examined at different rates. Fruit yield values were found to be higher in conventional fertilizer than in organic fertilization, and the amount of fruit juice increased in inorganic fertilizer application. When organic applications are evaluated among themselves, it is seen that as the amount of organic fertilizer increases, the amount of usare increases; It has been determined that the amount of fruit juice acidity and water-soluble dry matter, which are closely related to taste and aroma in fruit, increases compared to inorganic fertilization with the effect of organic fertilizer applications (Eryılmaz et al., 2010).

Göktekin and Ünlü (2016) found that green manure application can be used in organic tomato cultivation as an alternative to farm manure application; They also emphasize that the success rate will increase if plant activator and microbial fertilizers are combined with green manure.

The main cover crops recommended to be used for green manure that can be done between gardens are; common vetch, hairy vetch, Hungarian vetch, big vetch and fodder pea. However, in the selection of products to be included in the rotation; root systems (deep and superficial) and the amount of plant residues they will leave, the ratio between plant biomass above and below the soil (Govaerts et al., 2007), and the amount of nutrients it removes from the soil (Huang et al., 2003; Li et al., 2011) should be taken into account that it varies quantitatively and qualitatively according to plant species. Importantly, differences between plant species can occur greatly due to differences in plant growth characteristics due to soil temperature and soil moisture (Jiang et al., 2015). Studies show that green manure in vineyard areas should be considered from an anthropogenic point of view and that yield capacity can increase (Wittwer et al., 2017; Zanzotti and Mescalchin, 2019).

Geren et al. (2010) found that in green manure to be applied to vineyard areas, grains that grow upright and have a solid stem

It is recommended to grow broad beans as a mixture with leguminous forage crops with creeping-climbing characteristics. When the yield and quality characteristics of the specified green manure plants in grapes are examined; It has been reported that care should be taken especially if the plants are used in green manure, while these mixtures add more than 20 kg/da of organic nitrogen to the soil, due to the fact that this amount is too much for the vine plant, its vegetative parts develop excessively, reduce the grape yield, and may cause the expected benefit not to be fully seen the next year.

RESULT

Today, mineral fertilizers in conventional agriculture are used extensively in production areas because they provide various advantages in terms of application practicality for the producer. Considering the general structure of crop production in Turkey, although it is not possible for producers to give up mineral fertilizers, it is aimed to make applications in a more sustainable framework. In addition to raising the awareness of the producers in reducing the problems related to the current agricultural production, the production models to be recommended are primarily; Based on the nature of Turkey’s agricultural enterprises, it should allow the producer habits to be changed indirectly, taking into account the economic and ecological aspects of the producer, and the ecosystem elements.

In recent years, ecological intensification (strengthening) practices to ensure ecological sustainability in agricultural production are often cited as strategies to push production systems towards flexibility; Instead of chemical and energy inputs from outside, it is aimed to make use of ecosystem processes. For this purpose, practices such as green manures and cover crops are considered as ecosystem elements of ecological empowerment, as they have the potential to reduce and substitute the use of synthetic inputs.

While green manure applications in plant production vary according to the single and perennial nature of the cultivated plant grown, green manure plants should be included in the rotation program depending on the production planning in vegetable cultivation, and green manure plants should be preferred in the areas between the rows in orchards and vineyards established with perennial plant species.

CHAPTER 8

USE OF GREEN FERTILIZER IN WEED CONTROL

ENTRANCE

Weed management is a critically important activity in both agricultural production areas and non-agricultural areas. In agricultural production areas, weeds cause significant losses worldwide as they compete with cultivated plants in terms of light, nutrients, ground and water. Among all pests in plant production, weeds rank first in terms of yield and quality losses worldwide. In fact, it can be more than all the damage caused by pathogens and insects that cause disease in plants. When weeds are not controlled, yield losses of approximately 33-53% occur in crops (Oerke and Dehne, 1997; Karim, 1998). Even after farmers apply traditional weed control methods, 13-30% of the crops in their fields are lost (Swarbrick and Mercado, 1987). Weeds are also toxic to livestock and complicate agricultural production activities, as well as increasing production costs on farms (Bellache et al., 2022). In addition, weeds are one of the most important obstacles to sustainable agricultural production and global food security (Oerke, 2006). These plants, which are extremely competitive with cultivated plants, not only cause significant yield losses; at the same time, they complicate cultivation practices that are normally carried out for crop production (Zimdahl, 2018). Therefore, weed control is an important issue in terms of sustainable agricultural production and environmental safety. However, many weeds that are being practiced

Although there are control methods, not all of these methods are sustainable or healthy for the environment.

Although there are many methods used to eliminate problems caused by weeds, one of the most effective weed control methods is the use of herbicides. However, herbicides cause serious environmental problems. As a result of the use of synthetic herbicides as a stand-alone weed control method in weed control over the years, many weed species resistant to these herbicides have emerged worldwide (Bagavathiannan and Davis, 2018). Resistance problems have occurred in 165 different active substances against 21 of the 31 known herbicide mechanisms of action. Of the 267 weed species that have become resistant to herbicides, 154 are broad-leaved and 113 are narrow-leaved weeds, and these have become resistant in 72 different countries among 97 different cultivated plants (Heap, 2022). Most weed species have developed resistance to all of the mechanisms of action of existing herbicides. In the fight against these weeds, it is necessary to develop herbicides belonging to new mechanisms of action. However, no progress has been made since the last three decades (Duke, 2012). The main reason for the development of cultivated plants resistant to herbicides; Although it is an easy and effective weed control, it has ultimately resulted in an increase in the number of herbicide-resistant weeds. As a result of the gene flow from herbicide-resistant cultivated plants to related weed species, the problem of resistance has become increasingly inextricable (Ohadi et al., 2017). Therefore, it is clear that the problem of herbicide resistance cannot be avoided by using more herbicides. Therefore, it is extremely important to develop and implement sustainable weed control methods. However, environmental problems caused by practices used in weed control, resistance developed by weeds to herbicides, increasing weed spread rates through commercial activities, changes in climatic and land use make weeds even more problematic.

Widespread use of new approaches is needed for weed management to be successful in the coming period (Liebman et al., 2016). Therefore, the demand for environmentally friendly methods and products is increasing (Duke et al., 2022). In order to meet these demands, it is necessary to develop different control methods and to reveal the possibilities of using these methods together with herbicides. Because of these demands, it has led weed scientists around the world to develop ecologically based weed management tools (Chauhan and Gill, 2014). One of these environmentally friendly methods is the use of green manure plants. Since green manure plants naturally have the ability to inhibit the growth of weeds, they are preferred by producers in the control of weeds. Green manure plants do this by disrupting the ideal growth environment and life cycles of weeds, preventing weeds from developing by taking the important nutrients and water they need (Soomoro, 2020). Allelopathy plays an important role in the suppression of weeds with green manure. Numerous cultivated plants and weed species produce secondary metabolites known as allelochemicals, and the process is known as allelopathy. Allelochemicals can be used to control weeds in agricultural systems by using allelopathic cultivated plants for co-sowing or mixed sowing, crop rotation or mulching. There are many plants with high allelopathic potential, with a few important cultivated plant species such as wheat, rice, sorghum, rye, barley and sunflower. The allelochemicals naturally produced in these products can be used to suppress weeds and achieve an environmentally friendly and sustainable agricultural production system (Farooq et al., 2020).

Many cultivated plants are used as green manure. At the beginning of these, legumes, mustard and many medicinal and aromatic plants can be used effectively in weed control. In addition to improving the soil structure by adding organic matter to the soil, green manure plants can also be used in weed control because some cultivated plants belonging to the legume and mustard family can effectively suppress weeds (Al-Khatib and Boydston, 1999). In crop production areas, plant development, product yield and quantity, soil nutrients and the environment are all affected by the fertilizers used. Increasing chemical fertilizer prices and decreasing soil fertility are increasing the importance of using legumes as a source of organic fertilizers to increase soil fertility in the long term. It has been shown that the effect of mixing plants into the soil as green manure continues even in the third year, leaving the nutrients necessary for the plants in the soil (Talgre et al., 2012). In the use of legumes as green manure, it is known that if a non-leguminous cultivated plant is grown after itself, all the nitrogen needs of that plant can be met (Guldan et al., 1997). For this purpose, many cultivated plants, both legumes and non-legumes, are used as green manure. Although many legume species are used at the beginning of these, trifolium species (Trifolium spp.) are in the first place. Brassica campestris L., Brassica hirta Moench, Brassica juncea (L.) Czern., Brassica napus L., Brassica nigra (L.) Koch. and Lepidium sativum L. are commonly used as non-leguminous green manure for effective weed control  (Boydston et al., 1994; Al-Khatib and Boydston, 1999). This is achieved by the presence of volatile glucosinolates in plants and their binding to breakdown products such as isothiocyanates, nitriles, epitinides and ionic thiocyanates (Vaughan and Boydston, 1997). These glucosinolates are common and potent germination inhibitors in seeds and can be used as promising bioherbicides (Brown and Morra, 1995; Vaughan, 1999). However, the degree of weed suppression by cruciferous crops depends on the type and variety of the green manure plant and the seed size of the target weed species (Al-Khatib and Boydston, 1999). Even the glucosinolate content can vary depending on the type and variety of plants (Eberlein et al., 1998). Green manure plants also play an important role in crop rotation. In many aspects, green manure plants, which are taken into planting rotation, can suppress weeds, and it is even more important to use them in the control of weeds, especially those identified with some cultivated plants. At the same time, it is an important issue to use green manure plants especially in cleaning soils contaminated with herbicides. Here, it is also possible to use green manure plants to eliminate the toxic effects of herbicides mixed with the soil on some cultivated plants that are taken into planting rotation. Many plants used for green manure regulate the soil structure and play an effective role in the control of weeds. However, it is important to choose and use suitable plants. In this section, the importance of green manure in weed control is emphasized.

• CROP ROTATION AND GREEN FERTILIZATION

Crop rotation is defined as the successive cultivation of different plant species on the same land (Bullock, 1992). In this cycle, also known as crop rotation or rotation, crop rotation is characterized by a cycle, while the order of products to be grown in the same field is limited to growing in a certain period of time (Leteinturier et al., 2006). Here, it is not considered appropriate to grow the same product in the same field in a certain period of time. In addition to many advantages of farmers producing in this way in terms of plant protection, it is also extremely important in terms of economy (Dury et al., 2012). It is also an important strategy used to prevent crop losses caused by weeds. Because there are certain weeds that are identified with certain cultivated plants. For example, water-loving weeds are a serious problem in paddy cultivation. It is reported that the rotation of green manure crops such as cowpea with paddy has a significant decrease in the dry matter amounts of these weeds (Musthafa and Potty, 2006). When the paddy plant is planted with cultivated plants grown in arid conditions, a decrease in weeds that love water or are more of a problem in irrigated environments may occur. It is possible to prevent the damage caused by such weeds by choosing cultivated plants, taking into account the life cycles and environmental demands of these weed species in the sowing rotation. Because the order of cultivation of cultivated plants included in crop rotations greatly affects the weed flora (Teasdale, 2018). With crop rotation, there are serious reductions in the coverage area, density and biome of weeds (Marenco and Santos, 1999). It has been revealed that in the cultivation of perennial forage crops such as alfalfa, changes occur in the weed flora depending on the age of the alfalfa, perennial weeds increase over time and annual weeds decrease (Özmen, 2019). It is important to grow the species and varieties of cultivated plants, taking into account the weed flora and the dominant weed species.

The inclusion of legumes in the crop rotation of cultivated plants is beneficial in many ways. In particular, green manure plants to be selected from legumes should be brought to the fore. As it is known, leguminous green manure plants accumulate nitrogen in the soil through biological nitrogen fixation and increase soil fertility. It is also known that green manure plants deplete the weed seed bank in the soil (Melander et al., 2020). Especially in organic product cultivation, where weed control is much more difficult, a green manure application with legumes can reduce the weed problem in annual cultivated plants (Melander et al.,

2020).      Season   Grown throughout the only          annually or    also  Perennial

including legumes separately or their mixtures or mixtures with wheat               Weed Seed Bank Important              To a degree

can reduce. Such mixtures can be much more effective especially if they are grown for more than one year (Sjursen, 2001). Annual weeds that emerge in well-grown and regularly mowed green manure plants can disappear quickly. Lack of tillage and regular mowing of green manure makes it more difficult for these annual weeds to emerge with the regrowth of their plants (Davies, 1997). During the growing period of green manure, the introduction of new weed seeds into the seed bank is minimal, and most annual weed seeds with relatively short life spans (Bohan et al., 2011) can cause a significant decrease in the seed bank in the soil. By taking perennial leguminous forage crops into crop rotation with grains for a long time, weeds are suppressed, the amount of seeds falling into the soil decreases, and it creates a good growing environment for the cultivated plants to be grown after them, providing increases in yield and quality (Arlauskienė et al., 2021).  In places where annual weeds such as wild oats (Avena fatua L.) and wild mustard (Sinapis arvensis L.), which are a problem in many cultivated plants  , are dense, it is possible to control these weeds by taking the alfalfa plant into planting rotation in order to reduce the population of these weeds (Özmen, 2019), and mixing it with the soil as green manure after a certain year is beneficial for the cultivated plant to be grown after it Will. Weed control is costly in terms of labor, time and economy. Although modern plant protection methods are applied, weeds in many cultivated plants cause significant yield and quality losses and increase production costs. Taking into account the characteristics of weeds, it is possible to reduce their population by taking green manure plants into the crop rotation.

• USE OF LEGUMES AS GREEN FERTILIZER IN WEED CONTROL

In the legume family, there are edible legumes that have a very important place in human nutrition, as well as legume forage crops, which have an extremely important place in animal nutrition. One of the most important features of legumes is undoubtedly that they bind free nitrogen in the air to the soil. The germination of seeds can be affected by physical and biochemical changes in the soil profile where the seeds are located due to green manure plants mixed with the soil. One of the two main physical effects of the plant residue remaining on the soil surface is the decrease in the light reaching the soil surface and the other is the protection of the soil surface by covering it with plant residues. Maintaining the soil surface has effects on both soil temperature and humidity (Varma et al., 2017). Grain legumes are likewise able to minimize yield losses due to weeds by delaying the germination of weed seeds through allelopathy, reducing the weed population and weed growth. This is especially evident on weeds, whose seeds are relatively smaller (Liebman and Davis, 2000).

Different edible grain legumes (lentils, black-eyed peas and lupines) are known to suppress many weeds and reduce their populations due to their competition with weeds or due to their allelopathic chemical properties that they secrete. For example, soybean plant waste has been reported to suppress and inhibit weeds and increase the yield and quality of summer squash (Cucurbita pepo L.) and tomatoes (Solanum lycopersicum L.) (Barker and Bhowmik, 2001). In addition, aqueous extracts from plant residues of lentils had a suppressive effect on weeds that are problematic in wheat, such as field maple (Thlaspi arvense L.), tufted bromine (Bromus tectorum L.), and tall broomweed [Descurainia sophia (L.) Webb.]. While suppressing these weeds, it has been shown that it does not have any phytotoxic effect on wheat, and it is seen that lentils can control these weeds without the need for herbicides in wheat (Moyer and Huang, 1997), especially by using them as green manure and mixing them into the soil.

Hairy vetch (Vicia villosa Roth) is an important forage crop in the legume family and is widely grown as a cover plant and mixed with the soil and used as a source of green manure (Seo et al., 2000; Tosti et al., 2014; Kandel et al., 2020; Deguchi et al., 2022). Teasdale and Daughtry (1993) reported that hairy vetch reduced weed density by 70±78% and weed biome by 52±70% compared to fallow application in a study they conducted to suppress weeds by using hairy vetch as a winter annual cover crop. It is often not possible to physically control weeds in plants such as cereals, which are planted in large areas and have narrow rows and rows. Therefore, weed control depends on the use of synthetic herbicides. This brings with it many problems. Although the use of these chemicals is common in conventional agriculture, this is not possible in organically produced products. In organic grain production, weeds become even more important in terms of having a limiting effect on the yield and quality of the product for several reasons. The use of synthetic chemical herbicides and especially nitrogen-based fertilizers is not considered appropriate and many weeds such as red-rooted cockscomb (Amaranthus retroflexus L.) (Blackshaw and Brandt, 2008) have competitive advantages with cereals in terms of nitrogen. Compared to conventional production, weed density, prevalence, and biomass formation are generally higher in organic agriculture (Cavigelli et al., 2008; Ryan et al., 2009; Teasdale and Cavigelli, 2010). Therefore, there may be serious decreases in yield and quality. Although there are many advantages of growing legumes as a cover plant and then mixing them with the soil or using them directly as green manure, it becomes even more important to use them, especially in case of nitrogen deficiency in the soil (Amossé et al., 2013; Coombs et al., 2017). Such practices provide long-term success in weed control (Melander et al., 2005) and the role of using legumes as cover plants is extremely important in order to prevent weed infestations in the following years by reducing the soil seed bank.

Cover plants are used to create a physical barrier over weeds (Teasdale and Mohler, 2000) and compete for light (Carof et al., 2007; Kruidhof et al., 2008; Teasdale et al., 2007).  Some leguminous forage crops, such as alfalfa (Medicago sativa L.), can suppress weeds due to the allelochemicals they secrete (Xuan et al., 2003; Weston and Inderjit, 2007). At the same time, it reduces the number of seeds in the soil by increasing weed seed predetation by creating suitable habitats for vertebrates that feed on weed seeds in the soil (Meiss et al., 2010) and accordingly, it can reduce the weeds that will emerge in the following years.

However, while leguminous forage crops contribute to the sustainability of agricultural products through biological nitrogen fixation, they can also make significant contributions to biodiversity in the ecosystem by improving soil quality (Scholberg et al., 2010). It is seen that the use of legumes as green manure, especially to meet the nitrogen needs of plants, as well as some legume species can be used effectively in the control of many weeds.

USE OF MUSTARD AS GREEN FERTILIZER IN WEED CONTROL

Also known as mustard or cruciferous vegetables (Brassicaceae/Cruciferae family), the family is a large family containing many cultivated plants, ornamental plants and weeds (Lawrence, 1951). Cruciferous vegetables are used as green manure in terms of suppressing weeds and regulating the structure of the soil (Grossman, 1993; Boydston and Hang, 1995; Brown and Morra, 1995). The most important features of mustard vegetables in the use of green manure for weed control are their allelopathic effects. Some plants belonging to this family have high allelopathic potential over other plants (Fenwick et al., 1983; Velasco et al., 2008; Del Carmen Martinez-Ballesta et al., 2013). They mainly produce glucosinolates, which are biologically inactive under normal conditions. When plant tissues and cells are disrupted, they are hydrolyzed by the enzyme myrosinase (myrosinase); which in turn breaks down into various products, including isothiocyanates, nitriles, thiocyanates, epithionitriles, and oxazoliolines (Bones and Rossiter, 2006). The main breakdown products are isothiocyanates, which are phytotoxic (Fenwick et al., 1983; Fahey et al., 2001; Bennett et al., 2002; Kim and Ishii, 2006; Del Carmen Martinez-Ballesta et al., 2013). The proportions of these allelochemicals, which have a phytotoxic effect, in plants belonging to this family vary according to different organs of the plant. It is reported that the proportion of glucosinolates found in the seeds of mustard vegetables is higher than in the leaves, stems and roots of plants (Fahey et al., 2001; Velasco et al., 2008). Due to these allelochemicals, these plants have a high potential to be used as green manure and mixed with the soil to affect germinating seeds, as well as the potential to be used as bioherbicides considering these chemicals. This situation has also been revealed by the studies. Especially arugula plant is preferred in the use of mustard in the control of weeds. It is known that the powder obtained from the seeds of arugula (Eruca sativa) and akmustal (Sinapis alba) has a herbicidal effect against blue-flowered monsterweed (Orobanche ramosa), which is one of the most important weeds that are a problem in tomato growing areas (El-Masry et al., 2019). Again, the extract obtained from the alcohol-treated fresh shoots of arugula (E. sativa) was sprayed on the leaves to reduce the growth of one or two weeds, which were addressed on the two important weeds  of pea (Pisum sativum) production areas, Phalaris minor and Beta vulgaris weeds, and reported that the effect increased with the increase in concentration (El-Wakeel et al., 2019). Similarly, the effect of phenolic compounds and glucosinolates of seed powder of arugula and another mustard (Sinapis alba) as natural herbicides is shown to be related to lupine/white lupine (Lupinus albus) and two important weeds, Phalaris minor and Malva parviflora It has had an effect on it; they stated that both mustard algae are effective on both weeds, but the allelopathic effect is higher if both mustards are used together in a mixture (Abd El-Ghany et al., 2022). Canola (Brassica napus L.), which is also a plant belonging to the mustard family. When used as a green manure, it produced reductions in the biome of Amaranthus retroflexus, Chenopodium album, Setaria viridis and Convolvulus arvensis weeds (Hamzei et al., 2020).

In a study where mustard was used as green manure for the suppression of weeds in green pea cultivation, the suppression of weeds differed in green peas planted after rapeseed, white mustard, rye and wheat, which were planted in autumn and mixed with the soil. One month after planting, the highest weed growth was in wheat and the best weed suppression was seen in rapeseed. While rapeseed prevents the emergence of many weeds, it has also been observed that it causes a decrease in the emergence of peas in experiments carried out in a greenhouse environment (Al-Khatib et al., 1997).  It has been observed that Brassica juncea L. and Sinapis alba L. plants, which are used as green manure in  cowpea (Vigna unguiculata) cultivation, are grown as cover plants and mixed with the soil, and have  a suppressive effect on Eleusine indica and Digitaria sanguinalis,  which are narrow-leaved annual weeds that are especially common in the study area.

It has been reported that the success of using mustard as green manure to suppress weeds depends on the weed type, density and amount of seed bank in the soil (Norsworthy et al., 2005). In another study investigating the suppression of weeds by green manure and the yields of corn grown as animal feed, barley (Hordeum vulgaris L.) and triticale (Triticosecale spp.) from wheat crops and arugula (Eruca sativa L.) and canola (Brassica napus L.) from mustard crops  . They found that  wheat crops were more suppressive in their effect on Amaranthus retroflexus L., Portulaca oleracea L., Convolvulus arvensis L. and Alhaji camelorum L., which were dominant in the trial area in the use of wheat as green manure  . They reported that the dry biome of weeds resulted in an 85.3% reduction in barley and a 77.2% decrease in triticale compared to the control (Arazmjoo et al., 2022). Especially since Brassica spp. (B. hirta, B. juncea, B. nigra, B. napus) species can emerge quickly and develop strongly in the early period, they can control weeds by suppressing them in their early development periods. The release of allelochemicals from the shoots of living plants into the soil, the dispersal/secretion of plants and glucosinolates mixed with the soil by plant residues or tillage into the growing medium, and the hydrolysis of these glucosinolates to isothiocyanates inhibit the germination and growth of weed seeds (Al-Khatib and Boydston, 1999). Benzyl isothiocyanate, which is released by the breakdown of white mustard (Brassica hirta) and mixed with the soil, controls imam cotton (Abuthilon theophrasti) and kassiya (Cassia obtusifolia), an important weed belonging to the legume family, by having a phytotoxic effect (Dharamraj et al., 1994). Black mustard (Brassica nigra L.)’ Allyl isothiocyanate inhibits the germination of Bromus rigidus (Bell and Muller, 1973). Aqueous extracts from the decayed waste of wild mustard (B. kaber) can be used by Japanese millet (Eohinochloa crusgalli var. frumentacea) (Elliott and Stowe, 1971). Leaves of rapeseed (Brassica napus) mixed with soil controlled C. album, A. retroflexus and E. crus- galli weeds in a manner similar to standard herbicide applications  (Boydston, 1993; Boydston and Hang, 1995). It is seen that the use of mustard as a green manure source in weed control may be possible when the studies on this subject are examined.

USE OF MEDICINAL AND AROMATIC PLANTS AS GREEN FERTILIZER IN WEED CONTROL

Medicinal and aromatic plants are used for many purposes such as medicine, food, spices, tea, soft drinks, paints, cosmetics and resins. Due to the allelochemicals contained in these plants, they have the ability to affect the organisms in their environment (Mirmostafaee et al., 2020). With the increasing negative effects of synthetic herbicides in today’s agriculture, natural herbicides based on essential oils obtained from aromatic plants are gaining importance. Natural products such as allelochemicals are becoming increasingly important in controlling weeds, which are a problem in crop production (Duke et al., 2000; Weston, 2005; Narwal, 2010; Islam et al., 2022). Due to their allelopathic properties, these plants have an inhibitory effect on the germination and growth of different species, having a high overall species-specific advantage. Therefore, studies to determine the effects of these natural compounds on harmful weeds are constantly increasing (Bellache et al., 2022). In order to control weeds in sustainable agriculture, the phytotoxic chemicals produced by aromatic plants by using them as green manure and mixing them with the soil by taking advantage of their allelopathic properties (Dhima et al., 2009; Vasilakoglou et al., 2011). The effects of different medicinal aromatic plants on millet [Echinochloa crus-galli (L.) P. Beauv.], purslane (Portulaca oleracea L.), iron thistle (Tribulus terrestris L.), siren (Chenopodium album L.) and corn (Zea mays L.) were studied under field conditions by using different medicinal aromatic plants as green manure and mixing them with the soil. When the effects of ten different medicinal and aromatic plants selected from single and perennial species on the studied weeds were examined, it was reported that millet, purslane, iron thistle and vinegar reduced their effects on their output by 11-50%, 12-59%, 26-79% and 5883%, respectively, compared to the control plots, but there was no problem in the maize outlet (Dhima et al. 2009). In this study, it was observed that while the germination of weed seeds was prevented in the use of medicinal and aromatic plants as green manure, it was not effective on the growth and formation of green parts of weeds that emerged and grown. They reported that this situation is due to the rapid breakdown of allelochemicals in medicinal and aromatic plants mixed with the soil and the loss of their effects, and that weeds provide tolerance to the amount remaining in the soil (Dhima et al., 2009).

It is an important issue that the green manures of aromatic plants used in field conditions prevent the germination of weed seeds. Because in most cases, the results obtained under controlled conditions (petri and pot) cannot give successful results in field conditions (Dhima et al., 2009). In terms of practical application, sample applications of medicinal and aromatic plants will be beneficial to be applied by the producers according to the status of the existing weeds. For this purpose, plants belonging to the family of honeybabagiller (Lamiaceae) are mostly used. Ballıbabagiller famiya is a family that includes many broad-leaved plant species and is known for its species with many pharmacological and toxicological properties. In addition, many species of this family are important for their allelopathic activities in natural environments and laboratory conditions (Islam et al., 2022). Therefore, it is important for medicinal and aromatic plants belonging to this family to be used as green manure in the control of weeds and to have herbicidal effects. In a green manure study conducted with four different biotypes with high phenolic contents of the thyme (Origanum vulgare) plant, which belongs to this family, cotton (Gossypium hirsutum) and corn (Zea mays) were first used in planting and mixed with the soil and purslane (Portulaca oleracea), millet (Echinochloa crus-galli) and sticky grass (Setaria verticillata) decreased weed emergence by 55%, 52% and 86%, respectively, compared to control plots. In addition, the fiber yield of cotton and the grain yield of corn were found to be higher by 24-88% and 5-16%, respectively, compared to weed control plots without green manure (Vasilakoglou et al., 2011).

Considering the studies whose results are given above, we see that some medicinal aromatic plants provide control of some important weeds by mixing them into the soil as green manure or mixing them into the soil after using them as mulch. It has been shown that medicinal and aromatic plants can be applied as part of integrated weed control. Another issue to be considered here is whether the cultivated plant to be planted after the application of green manure is affected by the allelochemicals secreted by these medicinal and aromatic plants. The results of the studies carried out under controlled conditions should be tested in natural environments and promising results should be revealed. In addition, the effectiveness of green manure plants in weed control can be affected by many factors in the plant species (Mohammadi, 2012, 2013). Taking into account these factors, it is necessary to carry out studies on which type of green manure controls which weeds under what conditions.

PHYTOREMEDIATION OF SOILS CONTAMINATED WITH HERBICIDES WITH GREEN MANURE PLANTS

With the introduction of chemical fertilizers and pesticides in agriculture, there was a great increase in production and they were thought to be a great success and invention. However, with the gradual development of science, it has begun to be understood that these chemicals pose great negativities in terms of humans, animals and the environment. This issue has been frequently raised and seriously discussed, especially recently. However, it is understood that it is not possible to give up these chemicals, especially today when modern agriculture has become widespread. Because the problem of feeding approximately 9.7 billion people, which is thought to reach in 2050, is seriously faced by the world population, which is increasing day by day (Hossain et al., 2022). For this, it is necessary to find alternatives to these chemicals and to find ways to reduce the harmful effects of these chemicals. It has been an important issue that has been emphasized to reduce the chemical fertilizers to be used with green manure, as well as to remove the chemicals used from the soil by phytoremediation and to clean the soil. This is because soils are an important part of terrestrial ecosystems due to their critical role in ecological stability and agricultural production (Beiyuan et al., 2021; Zhao et al., 2021). The direct or indirect use of plants to remediate contaminated soils or water is known as phytoremediation. The concept of phytoremediation was formed by the combination of the Latin words “phyto”, which means plant, and “remediation”, which means healing, and is translated into our language as green breeding, treatment with plants, herbal treatment or herbal improvement (Tiryaki and Potur, 2017). This technology is a more economical, environmentally friendly, and generally accepted application for addressing the elimination of environmental pollutants (Arthur et al., 2005; Oladoye et al., 2022). The methods used in phytoremediation are classified according to the types of pollutants. If these pollutants contain metals, phytoextraction (Phytoaccumulation), phytostabilization and rhizofiltration; organic pollutants are grouped in six different ways: phytodegradation, rhizodegradation and phytocorrelation (Aybar et al., 2015). One of the important pollutants that are desired to be purified from the soil by the phytoremediation method is herbicides. Herbicides are synthetic soil pollutants that are used extensively for weed control in agricultural production areas. While a small amount of pesticides used in agricultural production, such as 0.1%, reaches the target pest to be applied, the remaining amount, 99.9%, is carried to the environment, where they adversely affect public health and beneficial bioorganisms; pollutes the soil, water and atmosphere of the ecosystem (Pimentel, 1995). Although this amount has decreased to a certain extent thanks to the recently developed technology, a very small proportion can still reach the target pest (Pimentel and Burgess, 2012). Herbicides are included in these pesticides and the same is true for them. With plants, especially soil

The phytoremediation of herbicides is gaining importance day by day and studies on this subject are increasing and important results are obtained. The use of green manure plants has an important place in phytoremediation. Many different plants can be used for this purpose. However, at the beginning of the characteristics that should be present in these plants, various physiological properties of these plants such as rapid growth, high biomass generation and high competitiveness are important for phytoremediation. Plants with these characteristics have the potential to be used as herbicide decontamination agents in soils contaminated with herbicides (Lamego and Vidal, 2007). Of course, not every green manure plant with these characteristics can be used effectively for every herbicide in the soil. The same plant does not show the same effect in the phytoremediation of herbicide with different active substances. For example, Crotalaria spectabilis, Canavalia ensiformis, Stizolobium aterrimum  and Lupinus albus, which are four different green manure plants used in the phytoremediation of herbicides with the active ingredient quinclorac and tebuthiuron, whose persistence in the soil is higher than the cultivated plant production season All of its plants absorbed more tebuthiuron from the soil than quinclorac (Mendes et al., 2021). Similarly, other studies have shown that some green manure plants can be used effectively in the phytoremediation of tebuthiuron-contaminated soils (Pires et al., 2003, 2005).

A plant that is sensitive to a herbicide is not suitable for use in the phytoremediation of that active substance. Plants belonging to the Cucurbitaceae, Solanaceae and Apiaceae families are sensitive to the herbicide with the active ingredient quinclorac (Rodrigues and Almeida, 2018). However, plants such as paddy (Oryza sativa), canola (Brassica napus L. and Brassica rapa L.), barley (Hordeum vulgare), corn (Zea mays), sorghum (Sorghum bicolor) and meadow wisteria (Poa pratensis) are tolerant to this herbicide. Since they are not affected by this active substance, they can be used in the elimination of quinclorac from the soil or in the phytoremediation of soils contaminated with the active ingredient quinclorac (Chism et al., 1991; Abdallah et al., 2006; Ferreira et al., 2012). In another study on the phytoremediation of this herbicide with green manure, Canavalia ensiformis (L.) DC., Cajanus cajan (L. Millsp.), Mucuna pruriens (L.) DC., Pennisetum glaucum (L.) R.Br. and Crotalaria juncea L. plants were used. Among these plants, the best results  were obtained from M. pruriens and P. glaucum plants (Ferreira et al., 2021).

In the phytoremediation of herbicides, herbicides with a long permanence in the soil are even more important. Some herbicides used in the control of weeds in a cultivated plant are in crop rotation                   to the next plant used      Phytotoxic             effect

can create. This is especially the case with a long half-life in the soil.                       Herbicides         for          even more                           Important.       Tebuthiuron             this

It is one of the herbicides. Since this herbicide is broad-spectrum and is used in many areas and has a half-life of more than two years in the soil, it is highly toxic and very dangerous to the environment and local habitats through residue problems, leaching, surface runoff (Rodrigues and Almeida, 2011; Christofoletti et al., 2017).

For such herbicides with high persistence, there is a need to research the most effective green manure plants and to conduct comprehensive research on this subject.

RESULT

It is necessary to increase the amount of agricultural production in order to meet the food needs of the increasing world population. Although there are many ways to increase this, it is perhaps the most economical way to prevent yield losses due to plant protection problems of the products we grow. Weeds have a very important place in plant protection problems. In some cases, it may even be possible to harvest the product due to weeds. There are many methods applied to prevent yield and quality losses caused by weeds. However, among these methods, the chemical control method with herbicides is mostly preferred because it gives fast results and is easy to apply. Unfortunately, the negative effects of chemical control on humans, animals and the environment are emerging day by day. In addition, as a result of the use of herbicides of the same mechanism of action in the same field for a long time, there are many weeds that have already developed resistance to herbicides around the world, and in some cases, it is not possible to control these weeds with herbicides. All these problems have led researchers working on weeds to alternative control methods to herbicides. There are many methods of struggle that can be an alternative to herbicides and they are applied. However, each of these methods has its own advantages and disadvantages.

Using green manure plants in weed control is an extremely environmentally friendly practice. For this purpose, many different plants belonging to different plant families are used. Among these, legumes play an extremely important role. The use of plants belonging to the mustard family is also extremely common. Of course, there are important medicinal and aromatic plants used for this purpose. All of these plants do not have a suppressive effect on all weeds. It is extremely important to choose green manure plants that are suitable for the weed situation and the cultivated plant to be grown. It is possible to take these plants in a proper order and to achieve very good results in the fight against many weeds. Green manure plants are not only used for weed control, but are also used as phytoremediation plants to clean soils and water contaminated by herbicides commonly used to control weeds. It is especially important for the phytoremediation of green manure plants in the elimination of problems caused by herbicides with long permanence in the soil. Using green manure plants in integration with other weed control methods will lead to successful results

CHAPTER 9

GREEN FERTILIZATION IN THE FIGHT AGAINST SOIL-BORNE FUNGAL DISEASES

ENTRANCE

The general concern for the future of food and agriculture is whether humanity can be sustainably fed until 2050 and beyond. This concern stems from the questioning of the social, economic, and environmental sustainability of food and agricultural systems (Anonymous, 2018). Global climate change, which threatens the whole world, the decrease in agricultural lands, yield losses in agricultural production and the increasing food prices accordingly strengthen the scenarios that crises related to food and water resources may arise in the future. However, the Food and Agriculture Organization (FAO) states that world agricultural production must increase by 70% to feed a population of 9 billion (Odegard and Van der Voet, 2014; Esetlili, 2019). For this reason, various solutions are being investigated for the development of global and regional agricultural systems for the future and to control the factors that cause crop losses in agricultural production. Plant diseases are considered to be one of the most important factors causing these crop losses. Plants are under the influence of biotic (fungi, bacteria and viruses) and abiotic (temperature, wind, humidity, light, precipitation and soil) factors throughout their lives (Scholthof, 2007). It is known that these factors are important components in the emergence of the disease, and a classic concept of plant pathology called the “Disease Triangle” emerges with the combination of a sensitive host, a virulent pathogen and suitable environmental conditions (Mazzola, 2002; Scholthof, 2007).

Soil-borne fungal diseases cause wilting, seed and root rot in many cultivated plants, causing 50-75% economic losses in greenhouses and fields. Members of this group, which includes factors such as Rhizoctonia spp., Fusarium spp., Verticillium spp., Sclerotinia spp., Pythium spp., and Phytophthora spp., have the ability to survive for many years in plant wastes or soil when their hosts are not present, thanks to their durable structures called microsclerotium, sclerotium, chlamydospore, and oospore (Panth et al., 2020;  Duff & Firrell, 2021; Parajuli et al., 2022). Sclerotium rolfsii remains alive in soil for 3-4 years (Kator et al., 2015), Sclerotinia sclerotiorum for 4-5 years (Adams and Ayers, 1979), Macrophomina phaseolina for 2-15 years (Gupta et al., 2012), Fusarium oxysporum for 10 years (Zhang et al., 2015) and Verticillium dahliae for 14 years (Schnathorst, 1981).

Considering the crop losses caused by the disease of plants, it is known that large-scale famines that result in the death of hundreds of thousands of people occur when diseases are not combated. For this reason, with the beginning of agriculture, various practices have been developed to prevent diseases in grown crops or to minimize the damage caused by disease factors. Methods of combating plant diseases are generally; legal, cultural, physical, chemical and biological. Chemical control is considered as the method that stands out with its effect in a short time and at a high rate. The pesticide journey, which started with the introduction of DDT (dichlorodiphenyl tricholooroethamine), continues to increase its global use with a total number of over 1000 pesticides despite all the known harms today (Choudhury and Saha, 2020). The negative effects of these widely used chemicals on nature cause environmental problems on a global scale, which brings along social and economic problems (Eryılmaz and Kılıç, 2018).

Among the most important inputs of agricultural production, fertilization, like pesticides, has an important place. With fertilization, the nutrients taken by the plants and the amount of nutrients in the soil are reduced by supplementing the soil and the agricultural soils are tried to be made fertile. In this sense, chemical fertilization, just like pesticides, contributes to production on the one hand and causes some negativities on the other. Considering these negativities, it is necessary to support fertilization with organic fertilizers (Sönmez et al, 2008). For this reason, organic fertilizers such as barn manure, compost and green manure have recently been actively used in agricultural production to enrich the soil with organic matter. Green manure stands out today as an effective resource due to its easy adaptability to different agricultural systems and ease of application (Karakurt, 2009). It is among the known benefits of green manure applications that increase the nitrogen concentration and the amount of organic matter in the soil, contribute to the increase of microorganism activity, increase the aggregate stability and water holding capacity of the soil, reduce pH levels, have positive effects on plant growth parameters and significantly increase yield levels (Wiggins and Kinkel, 2005; Yılmaz and Şahin, 2014: Maitra et al., 2018).

Green manure applications, which are generally used to increase the organic matter content of the soil, are especially successful in inhibiting soil-borne fungal pathogens. Green manures are considered as an effective alternative approach to chemicals in the fight against soil-borne plant diseases with their non-toxic, residue-free, highly degradable and decomposable properties (Baysal-Gurel et al., 2018; Saygı et al., 2019; Ziedan, 2022). Along with its effect on soil microbial communities, it inhibits the growth and survival of the pathogen using various mechanisms, causing a break in the host-pathogen cycle (Bailey and Lazarovits, 2003; Larkin, 2013). It has been recorded by many studies in the literature that pathogens that cause disease in plants are suppressed by green manure applications. In this section, we focus on the current situation of green manure applications used in the control of soil-borne fungal diseases in agricultural production.

HISTORICAL DEVELOPMENT OF GREEN FERTILIZER APPLICATIONS

The use of green manures as an agricultural policy has been accepted as a traditional method since ancient times (Larkin, 2013). The importance of green manure was emphasized in China in the 5th century BC; The Greeks and Romans, on the other hand, adopted this practice before this date. It was first defined by Pieters in 1927 as “the practice of enriching the soil by mixing fresh plant material brought in on-site or from afar into the soil” (Pieters, 1927; Manici et al., 2004). Although it has been noted that green manures improve the physical and chemical properties of the soil, there has been no mention of any effect on the fight against diseases and pests in these years in the literature. Later, in the 1950s, it was reported that green manure applications suppressed Verticillium wilt and common scabies diseases in potatoes, and  the concept of biofumigation was developed with the use of Brassica plants in green manure (Larkin, 2013). “Biofumigation” was first defined by J.A. Kirkegaard in 1993 as “the release of isothiocyanate compounds by hydrolysis of glucosinolate compounds present in plant tissues by incorporation of Brassica or related species into soil” (Matthiessen and Kirkegaard, 2006; Baysal-Gürel et al., 2018).

Methyl bromide, known as the most effective fumigant among broad-spectrum pesticides, is known as the most widely used pesticide against pathogens in soil fumigation before 2005. However, due to its negative effects on human health and damage to the ozone layer, the Montreal Protocol has made it mandatory to completely phase out this pesticide (Barry et al., 2012; Prasad et al., 2015; Baysal-Gürel et al., 2018; Ziedan, 2022). The damage caused by this non-specific fumigant to the environment has led to the research and development of alternative control strategies to this fumigant. At the same time, with the concept of sustainable agriculture, which has been used in recent years, it is seen that more environmentally friendly approaches have been adopted in the fight against diseases. For these reasons,

Therefore, especially after the 2000s, it is seen that the studies on the use of green manures in the fight against diseases have gained momentum.

BIOFUMIGATION AND GREEN FERTILIZER PLANTS

Some plants used in green manure are associated with biofumigation, and only one group of plants among hundreds of plant species is included in studies with their potential to become green manure (Chimouriya et al., 2018). Plant families used as green manure include Leguminaceae, Brassicaceae, Graminacae, Alliaceae,             Capparidaceae,        Tropaeolaceae,    Moringaceae,

The families Amaryllidaceae and Salvadoraceae are located (Ochiai et al., 2007; Karavina and Mandumbu, 2012; Larkin, 2013; Santos et al., 2021).

Among the above-mentioned plant families, plants in the Brassicaceae family are defined as the prominent plant group in biofumigation. These plants, which are native to the Mediterranean climate zone of the European continent; It was cultured about 4,000 years ago. This family constitutes a large group of plants consisting of approximately 338 genera and 3,709 species of scientific and economic importance, which are widely cultivated all over the world today. These plants, which are known to be used especially as oilseeds, green manure and animal feed, are also at the top of the list with their success in combating diseases and pests (Kirkegaard and Sarwar 1998; Bailey et al., 2006; Prasad et al., 2015). The specific effects of green manures on pathogens vary between different species and varieties of green manure plants, as well as under the influence of different environmental conditions (Larkin, 2013). In a study on this subject, it is stated that Brassica carinata contains higher levels of toxic compounds than other Brassica plants. It is known that this plant is more effective in the control of plant pathogens with its glucocyanate breakdown products, which are both water-soluble and volatile (Sintayehu et al., 2014). The plant species used as green manure and containing glucosinolates and the family names they belong to are given in Table 1 taken from Karavina and Mandumbu (2012).

Tropaeolaceae

Anonymous	Yaygın ismi	Familya
Alliaria petiolata	Sarımsak otu	Gao et al. (2018)
Arabidopsis thaliana	Fare kulağı teresi	Brassicaceae
Aziıııa tetracantha	Wang et al. (2022a)	Salvadoraceae
Scientific name	Common name in English	Above-ground biomass yield
N yield (kg/ha)	Source	Brassicaceae
Brassica fruticulosa	(KM, t/ha)	Brassicaceae
Brassica juncea	Hint hardalı	Crotalaria juncea
Sunn hemp	0.9-12.5	23-202
Jeranyama et al. (2000) de Resende et al. (2003) Mangaravite et al. (2014)	Glycine max	Soybean
2.8-5.8	49-141*	Thonnissen et al. (2000)
Brassica oleraceae	Lahana	Brassicaceae
Carda mine cordifolia	Singh et al. (2013)*	Lens-wide naris
Black lentil	0.6-2.7	17-64
Brandt (1999)	Papaya	Caricaceae
Diplot axis tenuifolia	Yabani roka	Vaisman et al. (2014)
Sesbania cannabina	Sesbania	12.1-37.0**
98-165	Bhardwaj and the Giant (1985)	(Syn.
Dliaincha	Moriııga	Moriııgaceae
Song et al. (2022)	Sesbania rostrata	Sesbania
0.95-5.82	26-181*	Becker et al. (1995)
Thlaspi arvense	Dliaincha	Brassicaceae
Tropaeolum majus	Shanna and Prasad (1999)	Tropaeolaceae

Brassica oleracea var in  the Brassicaceae family.Italica (broccoli), Brassica oleracea var. botrytis (cauliflower), Brassica rapa (turnip), Brassica napus (rapeseed), Brassica oleracea var. Major plants such as capitata (cabbage), Raphanus sativus (radish), B. carinata (Ethiopian mustard) and Sinapis spp. (mustard) are used effectively in the control of soil-borne diseases by producing sulfurous compounds called glucosinolates (Larkin and Griffin, 2007; Neubauer et al., 2014; Sintayehu et al., 2014). However, B.Q. Mulch® (Brassica nigra and B. napus), Biofum™ (a mixture of R. sativus and S. alba), Black Jack Radish™ (R. sativus), Black Mustard (B. nigra), BQ Mulch® (B. nigra and B. carinata), Caliente™ (Brassica juncea), Cappucchino™ (B. carinata), FungiSol™ (B. carinata and R. sativus), Mustclean™ (B. juncea), Nemat™ (Eruca sativa), Nemfix™ (B. juncea), Nemclear (B. napus), Nemcon™™ (B. napus), NemSol™ (R. sativus and E. sativa), Terranova Radish™ (R. sativus), Tillage Radish® (R. sativus), White Mustard (Sinapis alba), and Fumig8tor™ sorghum (Sorghum bicolor) (Duff et al., 2020; Duff & Firrell, 2021). For example, commercial fumigants named Caliente, Mustclean and Nemfix  caused  67-93% death in sclerots of the pathogen S. rolfsii, and commercial fumigants named Nemat and Tillage Radish  caused  93-100% death of the pathogen M. phaseolina (Duff and Firrell, 2021).

Apart from the Brassicaceae family, Leguminaceae plants are also among the popular agricultural products used in green manure with their high nitrogen fixing properties to the soil (Larkin, 2013). These plants fix atmospheric nitrogen through nitrogen-fixing bacteria present in their roots, thus enriching the soil with nitrogen for the next crop (Chimouriya et al., 2018). For example, red trifolium (Trifolium incarnatum), which is a legume cover plant, enters into a symbiotic relationship with the bacteria in the soil and fixes atmospheric nitrogen and is frequently preferred as a cover plant due to this ability. In this respect, it  has been determined to reduce the severity of root rot disease caused by Rhizoctonia solani, Phytopythium vexans and Phytophthora nicotianae (Parajuli et al., 2022). However  , the presence of large amounts of sulfur compounds in various parts of Allium species causes the remains of these plants to appear as a biofumigant product. It is known that dimethyl disulfide (DMDS), an important biofumigant obtained from Alliaceae members such as garlic, onion and leek, is  used effectively in the control of soil-borne pathogens such as Fusarium spp. (Arnault et al., 2013).

EFFECTS OF GREEN FERTILIZER APPLICATIONS

When all the control methods used in the fight against plant diseases are evaluated, it has been a matter of curiosity with which mechanisms the diseases are controlled and this issue has been tried to be clarified with various studies. As a matter of fact, knowing the mechanism of action of the preferred method will ensure that the struggle to be carried out is effective and sustainable (Mıstanoğlu et al., 2021). It is known that green manure applications used in the fight against soil-borne diseases are also effective through various mechanisms. Although biofumigation technically attempts to mimic the process using metam sodium or methyl bromide (Matthiessen and Kirkegaard, 2006; Baysal-Gurel et al., 2020), the mechanisms underlying biofumigation are considered to be much more complex (Motisi et al., 2010). In this application, the relationship between biological and physical parameters plays a role in the effectiveness of biofumigation. In addition to glucosinolate and other toxic compounds, the physical and chemical properties of the soil (pH, organic matter and clay content, etc.) have a direct effect on the struggle, while the microorganism activities in the soil have an indirect effect on this application (Mazzola, 2002; Motisi et al., 2010; Chimouriya et al., 2018; Parajuli et al., 2022).

Effect on Glucosinolate Production

Natural isothiocyanates, which are produced by plants belonging to various plant families and are released as a result of the hydrolysis of secondary metabolites called glucosinolates, which are rich in sulfur, have the potential to be used as fumigants and control pathogens with these properties (Poulsen et al., 2008; Santos et al., 2021). Glucosinolates activate the defense system of plants thanks to the large number of active ingredients they produce under the influence of the enzyme “myrosinase” (Prasad et al., 2015). This effect is attributed to the biocidal compounds they secrete into the soil, and as a result of hydrolysis, it has a detrimental effect on pathogens by releasing D-glucose, sulfate, isothiocyanate, organic cyanide, oxazolidinithione and nitrile (Bones and Rossiter, 1996;

Kirkegaard and Sarwar, 1998; Prasad et al., 2015; Campanella et al., 2020).

Although glucosinolates are divided into many groups according to the chain structure in their molecules, they are generally classified into three groups with different biological activities: aromatic, aliphatic and indole (Fahey et al., 2001; Prasad et al., 2015; Srivastava and Ghatak, 2017; Santos et al., 2021). Plants produce about 200 different glucosinolates, depending on their genetic makeup, growing conditions, and environmental conditions (Kakizaki and Ishida, 2017). This difference is also evident in the sensitivity of pathogens to glucosinolates (Clarkson et al., 2015). Table 2 shows glucosinolates identified in the Brassicaceae family from Prasad et al. (2015) and their major hydrolysis products.

Grup	Kimyasal adı	Yaygın ismi	Singh et al. (2013)*
	Jack Bean	0.6-6.2	16-213*
	3-Methylsulphinylpropyl	Glukoberin	ITC, nitril
	2-Propenyl	Sinigrin	ITC. nitril
	Kind	C/N	Source
	10.7	Kir	Trifolium resupinatum
0.5-11.6	Özyazıcı and Manga (2000)	Trifolium subterraneum	12.4-13.6
	Trigonellafoenum-graecum	9.8	Jalilian et al. (222b)
	9.8-13.8	Özyazıcı et al. (2009)	ITC. nitril
	Gatsios et al. (2021)	Vicia narbonensis	12.7-13.1
	Vicia saliva	11.0-11.3	Özyazıcı and Manga (2000)
	10.5-12.0	Kuo and Jellum (2002)	ITC
A rnm ot İL*	Jalilian et al. (2022b)	Hordeum vulgare	99.1
Laney and Janzen (1996)	Lolium mulliflorum	27.2-30.0	Kuo and Jellum (2002)
	p-Hydroxybeıızyl	Raheem et al. (2019)	Secale cereale
	Ranells and Wagger (1996)	Panicum maximum	22.6
Adekiya et al. (2022)	Penissetum glaucum	28.4	Watthier et al. (2020)
	4-Methoxy-3-indolylnıethyl	4-ethoxyglucobrassicin	Oksinler
	1 -Methoxy-3-indolylmethyl	Neoghıkobıasisin	Fitoaleksinler

•: isothiosiaiat

• Effect on the Production of Toxic Compounds

Toxic compounds produced by green manure plants reduce the population of pathogens. In this application, during the decomposition of organic matter in the soil, various toxic volatile substances such as formic, acetic and propionic acid are released in high concentrations and these toxic substances kill the resistant structures of pathogens (Conn et al., 2005). These compounds, which are released during the degradation of plant materials, reduce the V. dahliae population (Kowalska, 2021), and the pathogen is controlled by disrupting the structure of the microsclerotes of the agent with the production of volatile toxic compounds with antifungal effects (Conn et al., 2005; Ikeda et al., 2015; Panth et al., 2020). Similarly, it has been suggested that the resistant sclerotes of Sclerotium cepivorum may die or weaken  with toxic compounds released during the degradation of plants such as B. juncea and B. napus, making them more susceptible to attack by other mycoparasites (Smolinska, 2000). However, it is stated that the  disease rate of pathogens such as Fusarium spp. and Botryodiplodia theobromae decreases when the soil is rehabilitated with 1% propionic acid solution in  the greenhouse at the time of planting (Ziedan et al., 2020).

• Effect on Physical and Chemical Properties of Soil

Green manure applications are effective in controlling diseases by changing the physical and chemical properties of the soil (Larkin, 2013; Maitra et al., 2018). The soil contains the absolutely necessary nutrients for plants to continue their development in a healthy way, and in case of deficiency or excess of these nutrients, a suitable environment is created in plants against diseases (Genç-Kesimci et al., 2019). This practice increases the tolerance of plants to diseases by affecting the availability of nutrients such as nitrogen, phosphorus and potassium in the soil, as well as the amount of other nutrients such as manganese and zinc. As a matter of fact, it is known that Verticillium wilt disease is controlled with the increasing manganese content as a result of green manure applications in tomatoes and potatoes (Dordas, 2008).

Considering that there is a correlation between the degradation rate of pesticides applied to the soil and the pH of the soil (Matthiessen and Kirkegaard, 2006), the importance of soil pH in green manure applications also emerges. However, pH is known to be an important factor in glucosinolate hydrolysis (Bruggen et al., 2015). Ammonium, which is released by the breakdown of organic matter in alkaline soils, and nitrous acid, which is released by the breakdown of organic matter in acidic soils, change the pH of the soil (Ziedan, 2022). As a matter of fact, in a study on this subject, S. alba, B. rapa, E. vesicaria ssp. It   was determined that the pH value varied between 5.43-6.08 in the areas where sativa, B. juncea, B. napus and B. carinata plants were applied (Baysal-Gurel et al., 2020). Considering that Verticillium wilt disease is severe in neutral or alkaline soils (pH 6-9) and less severe in acidic soils, it is seen that soil pH is important in the control of diseases. Because decreasing soil pH  was associated with V. dahliae disease severity, it was stated that the highest disease level was observed in plots with a pH ≥ of 7.0 and the lowest disease level was observed in plots with a pH < 5.5 (Ochiai et al., 2008).

• Effect on Soil Microorganisms

Biofumigant products are effective by disrupting the life cycle of plant diseases. This effect can be directly caused by biocidal toxicity or indirectly through changes in soil fauna and microbial community (Srivastava and Ghatak, 2017).  As a result of the use of Brassica plants as green manure plants, the population of soil-borne pathogens decreases, and it is stated that the production of volatile sulfur compounds and changes in the soil microbial community are effective in this decrease (Larkin and Griffin, 2007; Campanella et al., 2020).

With the increase in the amount of carbon in the soil, the development of beneficial microbial populations is stimulated (Baysal-Gurel et al., 2018), thus increasing microbial activity and microbial diversity (Nair and Ngouajio, 2012; Meng et al., 2022). As a matter of fact, organic materials applied to the seedbed and root zone  cause changes in the amount of beneficial fungi and bacteria such as Bacillus spp., Enterobacter spp., Pseudomonas spp., Streptomyces spp., Penicillium spp., and Trichoderma spp. in these areas (Ziedan, 2022). This microbial community, which is collected in the root zone of the plant and is unique to the plant, promotes resistance to soil-borne diseases, thus increasing the chances of success in combating diseases (Mazzola et al., 2015; Srivastava and Ghatak, 2017; Lazcano et al.,

• . For example,  it has been argued that there is a parallel between the effectiveness of  buckwheat green manure application on F. oxysporum and the density of Streptomyces (Perez et al., 2008). Similarly, in a study in which Brassica napiformis and B. napus  plants were used in the control of V. dahliae,  it was determined that there was an increase in the rate of bacterial and fungal bioagents such as Pseudomonas, Flavobacter and Mortierella (Meng et al., 2022).  In another study investigating the effectiveness of Brassica juncea and Vicia villosa green manure applications on the fungal community of the soil, Cryptococcus, Entoloma, Olpidiaster, Waitea, Aspergillus, Fusicolla, Gibberella, Laetisaria, Coprinellus, Clonostachys,  and Arizonaphlyctis fungi have been found to be present in high proportions (Asghar and Kataoka, 2022).

These changes in both the structure and dynamics of the microbial population with green manure applications create a competitive environment for existing resources (Cohen et al., 2005), and at the same time, the pathogen population is suppressed by parasitism and antagonism mechanisms (Wiggins and Kinkel, 2005). As a result of these biological control mechanisms, plant diseases are successfully combated.  It is noted that there is a positive correlation between the loss of viability of the pathogen and the fact that green manures from S. bicolor and Fagopyrum esculentum promote the density of Fusarium graminearum antagonists and the development of their antagonistic abilities (Perez et al., 2008). Similarly,  it is stated that B. rapa and B. napus plants  are effective in controlling diseases by increasing the rate of successful bioagents such as Trichoderma (Ziedan, 2022). Same

It  is stated that  a synergistic effect occurs as a result of the co-application  of Trichoderma spp.  with B. juncea and the control of F. graminearum is achieved (Perniola et al., 2014). Tolerances of beneficial species such as  isothiocyanate Trichoderma  released from the pulp of the B. carinata plant were found to be higher than those of Pythium ultimum, R. solani and F. oxysporum pathogens, and it was emphasized that the bioagent was less affected by toxic compounds (Galletti et al., 2008; Srivastava and Ghatak, 2017). In this respect, Trichoderma, which is a bioagent that has proven its success in biological control against a large number of plant pathogens, is considered as an advantage that it is less affected by these toxic compounds.

• FACTORS AFFECTING THE SUCCESS OF GREEN FERTILIZER APPLICATIONS

Since each of the green manure plants is a species with special requirements and benefits, there are various factors that affect the success of these plants. In order to make the most of biofumigant products; Choosing the right variety, planting at the right time, doing soil analysis, knowing the development period of the biofumigant product well, adjusting the amount of seed to be planted in the soil, applying during periods when soil moisture is not high and having sufficient equipment are listed as the issues we need to know or pay attention to (Srivastava and Ghatak, 2017). In a study, it was determined that the effectiveness varied according to the amount of green manure applied, and  it was stated that the disease severity of V. dahliae was reduced by 70%  with the application of 24 mg/ha  of Pisum sativum, B. oleracea and S. vulgare, and the severity of the disease by 74% with the application of 12 mg/ha of P. sativum (Ochiai et al., 2007).

• Glucosinolate Level and Type

The level and type of glucosinolates associated with the success of green manures differ between various species (Bellostas et al., 2007; Karavina and Mandumbu, 2012; Duff & Firrell, 2021). For example B. juncea and B. nigra sinigrin, S. alba sinalbin, R. sativus glucoraphe and E. sativa It contains glucosinolates called glucoerusin (Srivastava and Ghatak, 2017), and it is known that not all isothiocyanates have the same toxicity considering the activity of biofumigant products (Neubauer et al., 2014). In a study B. oleracea, B. carinata, B. napus and Lepidium sativum Crops Fusarium oxysporum f.sp. cepaeTested against and B. carinata It has been determined that the plant significantly reduces the severity of the disease of the pathogen. Other of this plant Brassica The fact that it contains higher levels of glucosinolates than its species, as well as producing some of the biologically active isothiocyanate forms, is considered to be factors in this success (Sintayehu et al., 2014). Similarly, it is stated that the activity of 2-phenylethyl isothiocyanate on various fungi varies, Aphanomyces,              Gaeumannomyces,

It is stated that fungi such as Phytophthora and Thielaviopsis are more sensitive to this isothiocyanate (Smith and Kirkegaard, 2002). In another study in which the efficacy of allyl, benzyl, ethyl, 2-phenylethyl, and methyl isothiocyanates  on mycelial development and conidial germination  of F. graminearum in vitro conditions was tested, it was stated that allyl and methyl isothiocyanates were more successful (Ashiq et al., 2022). Similarly, it is emphasized that broccoli may be caused by the production of volatile antifungal substances such as allyl-isothiocyanate by broccoli residues in the reduction of microsclerot of V. dahliae (Ikeda et al., 2015).

• Soil Type

In soil, which is a highly complex and complex environment, the interaction of many factors affects the potential of glucosinolates (Matthiessen and Shackleton, 2005), and among these factors, soil type and soil environment cause variations in isothiocyanate release (Kirkegaard and Matthiessen, 2005; Baysal-Gürel et al., 2020). As a matter of fact, it has been observed that biofumigation gives better results in light soils with low organic matter content, as the movement of volatile substances decreases in heavy soils rich in organic matter (Bruggen et al., 2015).

• Setting the Application Period

The period in which green manure plants used in the fight against plant diseases are applied directly affects the success of this application. As a matter of fact, glucosinolate levels vary significantly in different periods of the year, with total glucosinolate levels being higher in the hot months of the year than in the cold months (Srivastava and Ghatak, 2017). This was supported by a study and  it was found that the mortality rate (67%-93%) in sclerots of the pathogen S. rolfsii in late winter/spring planting of B. juncea was higher than the mortality rate in autumn application (41%) (Duff and Firrell, 2021).

• Selecting the Appropriate Biofumigant Product

While pathogens are controlled with biofumigant plants, the negative impact of the existing cultivated plant will prevent the economic use of these plants. For this reason, it is necessary to pay attention to this issue, which is called phytotoxicity, when choosing biofumigant plants (Baysal-Gurel et al., 2020). At the same time, factors such as winter hardiness, growth rate, and the amount of glucosinolate produced at different times of the year are important in determining the most suitable biofumigant product (Neubauer et al., 2014). In addition, a plant species can show different activity in various pathogens. For example, while B. juncea was  effective by suppressing S. minor by 68%  and R. solani by 25%, the same plant  did not show effective biofumigation against Pythium spp. (Matthiessen and Kirkegaard, 2006).

Variations in the level of glucosinolates found in different tissues of a plant are observed with the effect of the development period and environmental conditions (Bellostas et al., 2007). In a study, the concentrations and distribution of glucosinolates in different organs of the B. napus plant were examined during plant development and it was determined that glucosinolate concentration was at different levels (Clossais-Besnard and Larher, 1991). When the glucosinolate contents of the roots and shoots were examined, it was found that there were differences in various ratios between both the same species and different species; It has been stated that aliphatic glucosinolates are predominantly present in the shoots and aromatic glucosinolates are predominant in the roots (Kirkegaard and Sarwar, 1998). In a study examining the root and shoot glucosinolate contents of many plant species, it was determined that the roots generally have higher concentrations and more glucosinolate diversity than the shoots. This is explained by the fact that the roots release isothiocyanates during both growth and decomposition, and the aliphatic isothiocyanates in the shoots are more volatile (Van Dam et al., 2009). For this reason, different biofumigation plants should be tried in order to provide an effective fight against the target pathogen. In particular, how biofumigation affects resting structures such as chlamydospores, sclerotes and microsclerotes  should  be tested in vitro and the best biofumigant product should be selected and then extensive field experiments should be started (Srivastava and Ghatak, 2017).

• Maximizing Isothiocyanate Release

The decomposition of plant tissues in the Moringaceae, Salvadoraceae and Tropaeolaceae families releases isothiocyanates, which are biocidal. Although plants have different isothiocyanate profiles, the breakdown of plants increases the amount of isothiocyanate produced (Karavina and Mandumbu, 2012). Glucosinolates contained in plants such as broccoli, cauliflower, mustard, rapeseed and horseradish release active chemicals such as isothiocyanate when the tissues of these plants are damaged and plant cells are broken down (Srivastava and Ghatak, 2017). For this reason, it is thought that the application of plant material by turning it into powder will be more effective than cropping. However, adding water to the soil immediately after application and covering the soil with a nylon will maximize isothiocyanate retention. It is suggested that up to 5% fresh produce is required to get the highest benefit from green manure plants, and 50 t/ha of green manure is generally required to achieve an effective result (Srivastava and Ghatak, 2017). In addition, after the application, the soil must be cultivated, toxic gases must be emitted from the soil, and crop planting should be done a few days later (Saygı et al., 2019).

• GREEN FERTILIZER APPLICATIONS IN THE FIGHT AGAINST SOIL-BORNE FUNGAL DISEASES

When the researches on the use of green manures in the fight against soil-borne fungal diseases are evaluated, it is seen that very successful results have been obtained against disease factors. Some of the studies in the literature are shown in Table 3, which was modified from Santos et al. (2021) and Ziedan (2022), and some of the studies are summarized below.

When the studies on this subject are examined, it is seen that soil-borne fungal diseases are generally emphasized in the literature. However, studies have shown that it is effective against several bacterial diseases (Table 3). Ralstonia solanacearum, the soil-borne bacterial wilt disease agent in tomato, is  one of the pathogens in which biofumigation is effective (Pontes de Carvalho et al., 2019).  Different parts of the Adhatoda vasica plant have been used as green manure in different doses against this pathogen, and successful results have been obtained in the fight against this disease, which does not have chemical control (Khan et al., 2020).

Kiran et al. (2020)

Patojen	Biyofumigant bitki	Konukçu	Kaynak
Rhizoctonia solani	Brassicajuncea	Şeker pancarı	Motisi ve ark. (2013)
	\ Brassicajuncea	Fasulye	Abdallah ve ark (2020)
	Brassica nigra	Patates	Rubayet ve ark. (2018)
	Brassica oleracea
Fusarium culmorum	\ Brassica carinata	Buğday	Campanella ve ark. (2020)
Fusarium oxysporum	Brassica oleracea	Soğan	Iriarte ve ark. (2011)
Fusarium graminearum	\ Brassicajuncea	–	Pemiola ve ark. (2012)
	\ Sinapis alba
Fusarium sp.	Brassicajuncea	Kudr et narı	Relevante ve Cumagun (2013)
Fusarium graminearum	\ Brassicajuncea	–	Pemiola ve ark. (2014)
Fusarium circinatum	Brassica carinata	Çam	Morales-Rodriguez ve ark. (2018)
Fusarium oxysporum f. sp.	Brassicajuncea	Salatalık	fin ve ark. (2019)
cucumerittum	Diplotaxis tenuifolia
Sclerotinia sclerotiorum	1 Brassica napus	Patates	Ojaghian ve ark. (2012)
	Brassicajuncea
	Brassica campestris
Sclerotinia sclerotiorum	Brassicajuncea	–	Warmmgton ve Clarkson (2016)
	Brassica napus
	Eruca sativa
	Raphanus sativus
	\ Sinapis alba
Sclerotinia homoeocarpa	1 Brassicajuncea	Çını	Pan ve ark. (2017)
Verticillium dahlias	\ Brassicajuncea	–	Neubauer ve ark. (2014)
	Brassica carinata	–	Wei ve ark. (2016)
	Brassicajuncea	Patates	Ochiai ve ark. (2007)
	Sorghum vulgare
	Pisum sativum	Patates	Davis ve ark. (2010)
	Zea mays
Phytophthora capsici	Brassica napus	Biber	Wang ve ark. (2014)
Phy toph th ora cinnamon! i	Brassica carinata	Meşe	Morales-Rodriguez ve ark. (2016)
Phytophthora cinnamomi	Brassica carinata	Bakla	Rios ve ark. (2017)
	Brassicajuncea
	Brassica napus
Phytophthora nicotianae	1 Brassica carinata	–	Serranoperez ve ark. (2017)
Phytophthora cactorum	Brassica carinata	Çilek	Banan ve ark. (2009)
Phytophthora brassicas	Brassica rapa	Çin lahanası	Cheahveark. (2001)
	1 Brassica napus
Pythium spp.	Brassicajuncea	–	Lazzeri ve ark. (2004)
Rhizoctonia soiani	Iberis amara
	\ Cleome hassleriana
Ralstonia solanacearum	Brassicajuncea	Domates	Pontes de Carvalho ve ark. (2019)
	Brassica oleracea	Zencefil	Bandyopadhyay ve Khalko (2016)
	Adhatoda vasica	Domates	Kiran ve ark. (2020)

It was determined that there was a decrease in symptoms caused by R. solani,  which causes root rot disease in landscape plants with Brassica applications, and there was no phytotoxic effect on plants for 4 weeks (Cochran and Rothrock, 2015). It has been determined that the V. dahliae population  decreases in soils treated  with B. oleracea and Sorghum vulgare (Ochiai et al., 2007).  Selected Brassica plants,  including B. napus, B. rapa, R. sativa, S. alba,  and B. juncea, R. solani, Phytopthora erythroseptica, P. ultimum, S. sclerotiorum, Fusarium sambucinum,  and F. oxysporumand it has been determined that it inhibits the development of these pathogens at different rates. Among these plants, it has been reported that B. juncea has a 100% inhibition rate against R. solani, P. erythroseptica and P. ultimum pathogens  in vitro (Larkin and Griffin, 2007).

In potatoes S. sclerotiorumAgainst B. napus, B. juncea and Brassica campestrisIn a study in which these plants were tried as green manure, it was found that these plants significantly reduced the severity of the disease. In the study, where it was stated that the results varied according to years and location, the highest effect was 55.6% B. junceahas this with a rate of 45.8% respectively B. campestrisand 31.6% B. napus(Ojaghian et al., 2012). In cotton V. dahliaeAs a result of mixing the green parts of barley, barley + vetch and vetch green manure plants with the soil during the flowering period, the rate of infection of the plant with the pathogen has decreased. In the study, green manure application of barley was the most effective application in reducing the severity of the disease, while the green manure application of vetch also reduced the severity of the disease (Erdoğan et al., 2012). In eggplant V. dahliaeAgainst B. napus, B. napiformis and as a result of a study in which carbendazim was applied B. napiformishas been found to suppress the disease at the same rate as the chemical (Meng et al., 2022). As green manure after wheat B. carinataIn the areas where Bipolaris sorokiniana and Microdochium nivale that their populations are 100% eradicated, Fusarium culmorum It was determined that the population was suppressed by 82%. However, compared to monoculture production, wheat yield increased by 9.5% to %              Increases ranging from 62.2 to 62.2 have been observed

(Campanella et al., 2020). As a result of the use of broccoli as a green manure V. dahliae In parallel with the 50% decrease in the amount of inoculum, there was a decrease in the severity of the disease (Ochiai et al., 2007), B. juncea Green manure applications V. dahliae’has been found to cause a 69.3%-81.3% reduction in microsclerot (Neubauer et al., 2014). B. napus, S. alba, B. juncea and B. carinataIn a study in which the biofumigation potential of was determined V. dahliae % of soil contaminated with microsclerotis                                                                                                                                                 0.4

These plants were added and it was  determined that B. juncea and B. carinata were effective in suppressing microsclerot. It was observed that there was a correlation between the content (82.8-108.1 μmol/g) of 2-propenyl isothiocyanate and the efficacy (62.5%-100%) of these species, which were named successful in the study (Neubauer et al. 2015).  In another study using alternative products such as BioFence   ™, the commercial form of B. carinata, and lavender wastes to reduce the amount of V. dahliae inoculum, it was determined that the plants tested as a result of both laboratory and field trials effectively controlled the pathogen (Wei et al., 2016). At the same time, green manure applications  have been recognized as a potential control strategy against two important diseases in potatoes, Streptomyces scabies and V. dahliae (Wiggins and Kinkel, 2005).  It has been determined that V. dahliae is suppressed by 60%-70% and potato yield is increased by growing sweet corn (Zea mays) as green manure for 2-3 seasons. Corn green manure applications have also  increased the population of several soil-borne fungi, such as Ulocladium and Fusarium equiseti (Davis et al., 2010).

Nevertheless B. carinataCommercial biofumigant obtained from , Phytophthora cinnamomihas been reported to suppress mycelia development and reduce the germination percentage of chlamydospore and zoospore (Morales-Rodriguez et al., 2016). S. alba, B. rapa, E. vesicaria ssp. Sativa, B. juncea, B. napus, B. carinata of cover crops R. solani and P. nicotianae It has been determined that they are effective in the control of factors. In the study, although the biofumigation period was applied for 2-4 weeks, similar results were obtained; As a result of this period, no phytotoxic effects were observed in the treated areas (Baysal-Gurel et al., 2020). In another study to determine the biofumigant potentials of onion and leek residues Allium of disulfide active molecules in species Pythium % of the factor                                            It has been announced that it suppresses 100

(Arnault et al., 2013). In addition, R. solani, the root rot agent in sugar beet, has  been identified as one of the pathogen groups in which biofumigation is effective (Motisi et al., 2013).

• THE IMPORTANCE OF GREEN FERTILIZATION WITHIN THE SCOPE OF INTEGRATED STRUGGLE

Significant advances are being made in both basic and applied sciences towards biofumigation research, this application is beneficially used in agriculture by producing substances similar to the active substances of synthetic fumigants by green manure plants. These advances show that biofumigation can be effective when applied to appropriate production systems and can lead to commercial adoption by providing cost savings. Despite this success, biofumigation is not considered to be a powerful and practical enough method to be an alternative to methyl bromide on a large scale in practice (Matthiessen and Kirkegaard, 2006). Because, as a result of the use of green manure applications in the fight against plant diseases, diseases are controlled to a certain level, and most of the time, full control of pathogens or pathogens cannot be achieved (Larkin, 2013). For this reason, green manures are applied as an important component in integrated struggle. This method of struggle envisages the application of biological, cultural, physical and chemical control methods in a way that complements each other (Khoury and Makkouk, 2010). As a matter of fact, the main purpose of this method of struggle; to reduce the use of broad-spectrum pesticides, to prevent damage to natural enemies, to prevent environmental pollution and to eliminate the problem of resistance to pesticides (Matthiessen and Kirkegaard, 2006; Khoury and Makkouk, 2010).

It is stated that when green manure applications are combined with other control methods, the potential to control diseases is quite high (Larkin, 2013). For example, since none of the control methods used against Verticillium wilt disease are effective alone, choosing an integrated control method including green manures in the fight against this pathogen provides more effective results (Ogundeji et al., 2022). Combining solarization with organic materials is considered an effective approach to combat soil-borne diseases. When a soil covered with plastic film and with the addition of suitable organic material is heated, the chain reaction of chemical and microbial degradation events is accelerated, which leads to the formation and increase of toxic compounds in the soil. These compounds accumulate under plastic mulch and are effective in combating soil flora and fauna by increasing their toxicity (Gamliel, 2000). As a matter of fact, by combining solarization and biofumigation, the population density of Pythium aphanidermatum decreased in greenhouses where cucumbers were planted, and it was determined that this practice had positive effects on the vegetative development of cucumber plants (Deadman et al., 2006).

• RESULT

In today’s agricultural practices, the non-renewal of organic matter in the soil after harvest is a very important problem. As the amount of organic matter in the soil decreases, problems such as productivity, erosion, disease and pests become common and it becomes more and more difficult to grow cultivated plants in a healthy way. In this case, fertilizers and pesticides are used at a higher rate for the continuity of agricultural production. Intensive use of agricultural inputs such as pesticides and fertilizers brings with it many problems that harm human and environmental health. Therefore, green manures are considered a “natural” alternative to chemicals to control various plant diseases. As a matter of fact, the development of both environmentally friendly and low-cost control strategies in the fight against plant diseases is very important for the current century. In this sense, green manure applications are considered as an alternative and successful method, especially in integrated struggle. Brassica plants stand out as prominent plants in this method, improving soil properties by increasing the amount of organic matter as well as their high biomass, and controlling plant diseases directly or indirectly with the biofumigation procedure. In particular, Rhizoctonia spp., Fusarium spp., Verticillium spp., Sclerotinia spp., Pythium spp. and Phytophthora spp., which is effective on soil-borne fungal pathogens, and this method gains importance when considering the difficulties encountered in the control of diseases.

In order to get more successful results in the fight against diseases with the use of green manure plants, it is necessary to pay attention to the selection of suitable plants and the time of application. However,  there is a need for local research into Brassica plants that can be used for biofumigation  and additional studies on the methods of incorporation of these plants into the soil. Breeding of Brassica plants with high isothiocyanate content  should be carried out, people working in agriculture should be informed about the benefits of this technique. In addition, although the fumigation mechanism is proposed in the effectiveness of green manure applications, different mechanisms should be revealed by researches.

CHAPTER 10

EFFECTS OF GREEN FERTILIZATION ON INSECTS

1. ENTRANCE

With the increasing world population, the requirements for agricultural products are increasing rapidly. However, the limited agricultural areas in the world and the decrease in yield and quality day by day and the decreasing sustainability of agro-ecosystems contrast with the population. While there is intense demand for agricultural products; It is expected that increasing drought, unconsciously used chemical fertilizers and pesticides disrupting the soil structure, diseases, pests and weeds reducing the yield and quality of the product will adversely affect the nutritional needs of human beings (Aksoy, 1999). Such expectations and negativities bring the sustainable natural balance to the forefront. In this natural balance, the soil, which is home to living things, especially plants, has an important place. Plant nutrients in the soil basically consist of two sources. The first of these; The elements in the structure of the main material that makes up the soil, and the other is organic and mineral fertilizers and plant residues added to the soil. The level and duration of these nutrients to the plants growing on the soil depends on the size of the nutrient store and the rate at which the elements in it are transformed into a form suitable for plants. Topsoil, which is the main growth site of the roots, largely meets both the water and nutrient requirements of the plants, and the physical properties of the soil can be changed with proper tillage and mixing of organic residues (Dormaar et al., 1986). In soils that are poor in organic matter, physical, chemical and biological interactions are insufficient. Supplementation of organic matter to soils; barn manure, green manure, compost, guano, urban wastes and other organic matter applications (Kacar, 1986). In addition to providing organic matter and plant nutrients to the soil with green manure applications; In particular, some basic physical properties of the soil such as biological activity, structure, pore size and distribution, infiltration improve, and suitable conditions are created in terms of plant growth (Özyazıcı et al., 1995; Kara and Penezoğlu, 2000; Özyazıcı and Özdemir, 2013). These conditions have positive effects on numerous macros and microorganisms in the soil.

Soils are an important source of the diversity of microorganisms in the world (Ramirez et al., 2018), as well as home to insects and various vertebrates and many other organisms (Bardgett and Van Der Putten, 2014). These organisms, or soil biota, include bacteria, actinomycetes, fungi and algae (microflora); protozoa and nematodes (microfauna); collembola, mites, termites, ants and other associated microorganisms and meso-fauna and flora (Osman, 2013). These creatures play a vital role in the soil and represent an important function in global biodiversity and the global ecosystem (Anonymous, 2005; Petchey and Gaston, 2006). Soil biota can mediate interactions between the host plant and above-ground organisms such as herbivores, predators and parasitoid insects, pollinators (Heinen et al., 2018). Interactions with soil organisms can also sensitize the immune system of plants so that they can respond faster or more strongly to subsequent attacks by antagonists (Pieterse et al., 2014). This process, better known as induced systemic resistance, may play an important role in plant-insect interactions (Saravanakumar et al.,

2008; Prabhukarthikeyan et al., 2014). It is estimated that the number of insect species described in the world is approximately 1 million, and approximately 4.5-7 million species have not yet been discovered (Stork, 2018).

Insects carry out 3 natural processes in the functioning of the ecosystem that are very important for the life of living beings. These; pollination of flowers, conversion of plant and animal organic matter into humus and its natural effects on harmful insects (Fox, 2013). One of the results of improving the physico-chemical and biological properties of the soil where green manure is applied is that it creates a more suitable habitat for insects. Therefore, soil structure has an impact on the population of insects living in the soil. Small soil beetles have a hard time moving through heavy clay or compacted soils (Anonymous, 2022). However, in looser and organic matter-rich soils, adults and larvae of insects can move more easily. The effects of green manure on insects can be beneficial or harmful. This may vary depending on the type of green manure used and the crop that will be grown later. Preferred green manure plants can increase the pest population as well as create a suitable environment for predator insects. Since it will create suitable living conditions in the soil structure, it can also cause many insects to gather in these areas. That is, in agroecology, the soil structure and the plants that grow here are quite important in the spatial distribution of insects. Since there are a very limited number of studies on the effect of green manure on pests, this section focuses on the effects of green manure plants on insects within the framework of soil-insect relationship.

• SOIL INSECT RELATIONSHIP

One of the main sources of organic change in soil is green manure. Organic matter is one of the most important components of soil, which plays an important role in improving the chemical, physical and biological properties of the soil (Fenton et al., 2008). Organic matter is the home and food of millions of living things, bacteria, fungi, algae, protozoa, insects, worms (Pieters, 2006). Soil is a complex of many factors that are separately and together vital for the life of insects. That is, topography, texture, structure, color, temperature, pressure, food, organic matter, nutrients, nitrogen, carbon dioxide, oxygen, moisture and natural enemies make up this complex. Some of these have little significance in the life cycle of soil-dwelling insects, while others have a significant impact. In general, it can be said that insects are directly or indirectly dependent on the soil, as it is the basis of all life forms (Mccolloch and Hayes, 1922). One or more biological periods of these insects continue in the soil. It seems that practically all of them, from primitive insects to advanced insects, are represented in the soil fauna. Although Thysanura and Collembola, as groups of soil-dwelling insects, are reported to be particularly abundant in the soil (Mccolloch and Hayes, 1922), almost all of the insects are associated with the soil.

To illustrate insects that cause economic damage to plants, the family Acrididae of the order Orthoptera lays its eggs in the soil. Locustidae and Gryllidae spend most of their lives in the soil. Numerous species of thysanoptera are found in the soil and on its surface. Species of the order Hemiptera are largely found in plants. However, many species belonging to Cicadidae and Aphididae and Coccidae feed on the root, and they are closely related to the soil. The families Galgulidae and Saldidae live in muddy areas, and Cydnidae shelter in the soil. Isolated species of Cercopidae, Fulgoridae and Membracidae are also found in the soil. The most striking soil group of the order Neuroptera is the Myrmeleontidae family. Their larvae form conical pits in sandy areas to trap prey. Trichopteras, while living in an aquatic environment, in some cases use sand or soil for their larval and pupal stages. The order Lepidoptera includes numerous species that inhabit the soil during varying periods of their life cycle. In most cases, pupading occurs only in the soil; The other stages are above ground. It occurs among certain species of Notodontidae, Geometrina, Sphingidae and Noctuidae. The larvae of many Crambidae live in burrows made of clods of earth. Some Noctuids, especially Agrotis spp., spend most of their larval stage in the soil. Larvae and pupae of families such as Tipulidae, Tabanidae, Leptidae, Asilidae, Bombyliidae, Therevidae, Dolichopodidae, Mycetophilidae and Bibionidae of the order Diptera are found especially in soil rich in organic matter. Tephritidae species, whose larvae are harmful to fruits, complete their pupal stage in the soil. Coleoptera represent one of the largest orders of insects, and families such as Carabidae, Cicindelidae, Silphidae and Staphylinidae in particular have a close relationship with the soil throughout their lives. Almost all species of Scarabaeidae, Elateridae, Lampyridae and Meloidae lay eggs, larvae, pupae and part of their adult stage in the soil.

Passes. A large number of species belonging to other families are also well represented in the soil fauna. Ants, bees and wasps from the order Hymenoptera represent many interesting groups of insects that live in the soil. Formicina, Sphecina and many Apoids dig wide tunnels, cavities or burrows in the soil, where they store food and raise their larvae. Adults of many Scoliidae species parasitize other insects and preserve them in the soil. Insects; It usually makes temporary use of the soil for shelter (summering, wintering, adverse climatic conditions, etc.), finding food or spending several of its biological periods. In addition, while they benefit by converting plant debris in the soil into organic matter, many of them also cause harm by feeding on plant roots. Soils with green manure create very suitable living conditions for Wireworms (Agriotes spp.). Growing potatoes in such areas can adversely affect production. However, in the fall, when wireworms are very active in the upper layers of the soil, plough and subsequent disking reduce the population (Gratwick, 1989). The seed fly, Delia platura (Meig.) (Diptera: Anthomyiidae), causes damage by feeding on the cotyledons of germinating seeds. Green manure can provide a suitable environment for spawning, as it will turn into organic material, which can have a significant impact on the amount of damage (Hammond and Cooper, 1993; Hammond, 1995).

Many species of insects from agricultural pests are in close relationship with the soil. Anisoplia species (Coleoptera, Rutelidae), females lay their eggs at a depth of 10-25 cm in light soils. The larvae usually stay in the soil for 2 years and cause damage by gnawing the root of the young grain plant under the ground. Syringopais temperatella Led. (Lepidoptera, Scythridae) females lay their eggs in clusters in cracks in the soil. The larvae spend the summer at a depth of 15-20 cm in the soil. Again in the soil, they pupate at a depth of 5-10 cm in the soil. Zabrus spp. (Coleoptera, Carabidae) spends the winter in the soil both as an adult and as a larva. Adults enter the summer in the soil on the hot days of summer. With the onset of rains in autumn, the adults that emerge from the soil begin to mate in the stubble, in the unplowed soil sections. Mating females lay their eggs one by one in small nests that they build in the soil. Young larvae feed by pulling crop leaves into the soil when they find suitable conditions in the autumn months. The damage of the larvae is directly related to the soil structure, especially with soil temperature and moisture; The degree of damage varies according to whether these parameters are suitable or not.

Porphyrophora tritici (Bodenheimer) (Homoptera, Margarodidae) lays its eggs in the ground. The larvae spend the winter in the soil lethargic. In the spring, the larvae that rise above the ground enter the leaf scabbard, where the leaf meets the stem. From here, they pass to the root collar and hold on. Although the plant develops normally in strong soil and high humidity, there is little or no grain yield. An effective cultural control can be carried out by placing legumes such as bushing, vetch, alfalfa and sainfoin in the order of planting. Pachytychius hordei Brulle (Coleoptera, Curculionidae) spends the winter in the soil as an adult. After spending summer and wintering periods in the soil for a period of about 8 months, it comes to the surface of the soil. The depth of the larva’s descent into the soil depends on the structure of the soil. Larvae of Agrotis ipsilon Hufn., A. segetum D.S. (Lepidoptera, Noctuidae) are subsoil pests. They lay their eggs, individually or in small groups, on the stems of host plants, on the lower surfaces of leaves, or on the soil surface. Mature larvae pupate, usually going 10 cm deep into the soil.  The larvae of Spodoptera exigua Hbn. (Noctuidae) pupate in or on the surface of the soil. Gryllotalpa gryllotalpa L. (Orthoptera, Gryllotalpidae) adults and nymphs destroy the roots of all kinds of plants they come across while opening galleries in the soil, it is the main problem of nurseries and gardens, and sometimes they cause very significant damage to irrigated soils. In May or June, females lay eggs in 2-3 nests, which they build from soil 10-20 cm deep in the soil. The resulting nymphs wait in the nest for a few weeks and then disperse. After changing two or three shirts, they retreat to wintering in the fall, going deep into the soil.

Tanymecus dilaticollis Gyll. Mature larvae (Coleoptera, Curculionidae) usually pupate in a thimble at a depth of 40-50 cm, depending on the soil structure. Adults are mostly seen in the soil starting from September and spend the winter in their nests in the soil. In April-May, adults cause significant damage by eating the leaves of newly emerging corn plants in the form of a half-moon and cutting the growth cones.

Wireworms such as Agriotes lineatus L., A. obscurus L. (Coleoptera, Elateridae) overwinter under grass piles in the cells they form in the soil. In the spring, the larvae approach the soil surface and feed on parts of the plant such as root tubers. Adult females lay their eggs 10-15 cm deep in the soil until mid-July. The hatched larvae immediately begin to feed. The larvae complete their development in the soil in about 4 years. In summer, they pupate in a cocoon, going 30-40 cm deep into the soil. Adults formed in the summer only emerge from the soil next spring. The larvae feed on the soil parts of the plants, causing serious damage.

Adults of Phyllotreta spp., Psylliodes spp. (Coleoptera, Chrysomelidae) spend the winter in soil, plant debris and under grass. Phorbia securis tiensuv. (Diptera, Anthomyiidae) prefer soils rich in organic matter and spend the winter in the soil in the pupal stage. Loxostege sticticalis (L.) (Lepidoptera, Pyralidae) spends the winter as a mature larva in a pupal cocoon at a depth of 5-7 cm in the soil. Lethrus brachiicollis Fairm. Adults (Coleoptera, Scarabaeidae) spend the winter in their nests opened to the soil surface with an upright gallery 5060 cm deep and 2-2.5 cm in diameter. They usually come to the surface of the soil in mid-March with the soil temperature at this depth being 10 °C. Adults build their new nest by digging a sloping tunnel 15-20 cm long. At the end of these galleries, they make a walnut-sized larval chamber. In these rooms, they store plant parts that they cut from various plants. The female lays one egg in the mouth of each larval chamber. The egg hatches in 9-11 days, the larva that emerges feeds on mud for 1-2 days, then enters the larval chamber and feeds on the stored nutrients for 25-30 days, then pupates in a sheath made of mud.

Helicoverpa armigera (Hbn.) (Lepidoptera, Noctuidae) spends the winter in the soil in the pupal stage. Ceuthorrhynchus denticulatus (Schrk.) (Coleoptera, Curculionidae) spends the winter as an adult at depths of 3-21 cm in the soil. Mature larvae pupate in the cocoon they form from the soil in the games they form in the roots. The larvae cause damage by opening superficial galleries in the roots 5-10 cm below the soil surface. In sandy and light soils, the number of adults and larvae of the pest is higher than in heavy soils. Earias insulana Boisd. (Lepidoptera, Noctuidae) mature larvae pupate between cocoon bract leaves, leaf folds or debris in the soil.  The mature larva of Spodoptera exigua (Hbn.) (Lepidoptera, Noctuidae) makes a thimble-shaped chamber in the soil at a depth of 4-7 cm. The larva weaves the entrance of this chamber with a web removed from its mouth and becomes a pupa here.

Thrips tabaci Lind. (Thysanoptera, Thripidae) larvae pupate at a depth of 1-6 cm in the soil. Antigastra catalaunalis Dup. (Lepidoptera, Pyralidae) spends the winter in the pupal stage in the soil or among the remains of plants that have fallen to the ground. Phthorimaea operculella (Zell.) (Lepidoptera, Gelechiidae) mature larvae pupate in a whitish cocoon between fallen leaves and plant debris and in the soil. The larvae of Ardis brunniventris (Hart.) (Hymenoptera, Tenthredinidae) overwinter in cocoons in the soil and pupate in early spring. Rhynchites hungaricus (Hbst.) (Coleoptera, Attelabidae) spends the winter in the soil at a depth of 2-8 cm in an oval-shaped cocoon as a mature larva.The larvae of Liriomyza trifolii (Burgess) (Diptera, Agromyzidae) pupate in the soil or attached to the leaf surface. Merodon eques (Fab.) (Diptera, Syrphidae) females lay their eggs one by one in the soil near the root collar of their host plants. The larvae are located at a depth of 5 cm from the soil surface of the pupae. Hypera postica (Gyllenhal, 1813) (Coleoptera: Curculionidae) spends winter and summer in the soil. Phragmacossia albida (Ersch.) (Lepidoptera, Cossidae) spends the winter as larvae inside artichoke roots. From the end of March, when the soil temperature rises above 15 °C, the larvae emerge from diapause and begin to feed.

Sphaeroderma rubidum Graells. (Coleoptera, Chrysomelidae) spends the winter in larval form among leaf debris or in the soil. The larvae pupate in mid-March at a depth of 1-3 cm in the soil. Etiella zinckenella Tr. (Lepidoptera, Pyralidae) spends the winter in the soil in a mature larva or prepupa in cocoon. Psila rosae F. (Diptera, Psilidae) spends the winter in the roots, usually in the larval stage or in the pupal stage in the soil. Females lay their eggs on the soil surface around host plants, close to the plant. Aulacophora foveicollis (Lucas) (Coleoptera: Chrysomelidae) females lay their eggs singly or in small groups in the immediate vicinity of the plant and under the ground. Upon reaching maturity, the larvae move to the soil and pupate in a thimble they make.

Myiopardalis pardalina Bigot (Diptera, Tephritidae) pupates at different depths (1–14 cm) depending on the structure of the soil in winter. Ceutorrhynchus pleurostigma (Marsh.) (Coleoptera, Curculionidae) lays its eggs in the main and lateral roots of the cabbage plant, the root collar and the soil around the root, depending on the plant type and soil structure. Depending on the soil structure, it pupates in the cocoon it makes by combining soil particles at a depth of 2-10 cm. Mamestra brassicae L. (Lepidoptera, Noctuidae) spends the winter in the soil in the pupal stage. Delia brassicae (Wied.) (Diptera: Anthomyiidae) overwinters in the soil in the pupal stage. Females lay their eggs singly or in groups of 2-3 in soil cracks around the root collar of young plants. Sitona species (Coleoptera, Curculionidae) lay their eggs on the soil surface. The larvae feed on plant roots in the soil. It spends the winter in the soil as eggs, larvae and adults.

Apion arrogans Wenck. spends the winter as an adult in diapause at a depth of 10-15 cm in the soil, in areas where weeds or shrubs, heathlands, mixed meadow grasses are present in and around the field edge. In case of sudden temperature drops, heavy rains and high temperatures, they usually go down to a soil depth of 3-5 cm around the root of the lentil. Smynthurodes betae West. (Hemiptera, Pemphigidae) spends the winter period in the soil, in the 1st larval stage in the cocoon. With the warming of the weather in March, the larvae, which become active, pass to the plant roots and begin to feed, and the larvae, which feed by sucking the plant sap, swell and become cysts.

Liriomyza cicerina (Rond.) (Diptera, Agromyzidae) spends the winter in the pupal stage at a depth of 3-6 cm in the soil. Leptinotarsa decemlineata (Say) (Coleoptera, Chrysomelidae) overwinters as an adult at a depth of 5–30 cm in the soil. Overwintering adults begin to emerge in spring when the average temperature at a depth of 10 cm in the soil exceeds 13 °C.

Tropinota hirta (Poda) (Coleoptera, Scarabaeidae) lays its eggs in humus-rich soils. It spends the winter in the soil in the larval and adult stage. The larvae feed on the roots of weeds. Having completed its development, the larvae pupate in a cavity in the soil, which they form within 6-9 weeks.

Cydia molesta (Busck.) (Lepidoptera, Tortricidae) spends the winter in the mature larval stage, under the bark of the trunks of trees, in crevices and cracks, in various shelters on the soil, in the crevices and fruit packing places they weave.Polyphylla spp. and Melolontha spp. (Coleoptera, Scarabaeidae) females lay their eggs in groups of 25-30 15-25 cm deep in the soil, especially in lightly grazed gardens that have not been cultivated for 2-3 years. The emerging larvae are first fed with soil humus. In between, they gnaw on grass roots and then feed voraciously on tree roots.

Rhagoletis cerasi L. (Diptera, Tephritidae) spends the winter as a pupa in the soil. Adults begin to emerge in late April or early May, depending on temperature and soil moisture. Caliroa limacina Retz. (Hymenoptera, Tenthredinidae) spends the winter in the cocoon 5-10 cm deep in the soil, in the larval and mostly prepupa stage. Capnodis spp. (Coleoptera, Buprestidae) adult females lay their eggs individually or in groups of 5-10 or more in cracks in the tree trunk near the root-collar, between the bark, in the grafts or in the soil around the root collar.

Anthonomus spp. (Coleoptera, Curculionidae) adults spend the winter under bark, stones, leaf debris or in crevices and cracks in the soil. Hoplocampa spp. (Hymenoptera, Tenthredinidae) spends the winter in the larval stage, in the cocoon, a few centimeters deep in the soil. Frankliniella occidentalis (Pergande) (Thysanoptera, Thripidae) spend their prepupa and pupal stages in the soil. Klapperichicen viridissima (Walk.) (Hemiptera, Cicadidae) nymphs complete their development in 5 years and remain under the ground during this time. Strophomorphus ctenotus Desbr (Coleoptera, Curculionidae) lays its eggs at the base of vines or in the soil. The emerging larvae move into the soil and feed on plant roots until the end of the year. It becomes a pupa in the chamber it makes in the soil. They spend the winter in the larval stage at a depth of 10 cm in the soil, near the roots of vines or weeds, in a nest they prepare in the soil. Otiorhynchus spp. (Coleoptera: Curculionidae) They lay their eggs at the base of vines or in the soil. After 15-20 days, the hatched larvae move into the soil and feed on plant roots. They pupate at the end of 8-10 months in the chamber they make in the soil. They spend the winter as adults under fallen leaves and vine bark in the soil. Sparganothis pilleriana D-S. As soon as the larvae of (Lepidoptera, Tortricidae) hatch, they spend the fall and winter without feeding in the soil and under dry leaves. Viteus vitifolii Fitch. (Hemiptera, Phylloxeridae) root phylloxera spends the winter in nymph on vine roots.

Insects that cause economic damage to cultivated plants spend a certain one or more biological periods actively or passively in the soil, and it is understood that this is closely related to the host plant and soil structure. At the same time, along with these insects, many parasitoid insects can survive in their host in the soil and become prey to predatory insects.

• EFFECTS OF GREEN MANURE ON INSECTS

Plants from the legume family, which are preferred as green manure plants, can be attractive to many beneficial and harmful insects. In addition to green manure plants such as alfalfa and vetch, Acyrthosiphon pisum (Harris), Aphis craccivora Koch., Plagionotus floralis Pall., Smaragdina limbata (Steven), Adelphocoris lineolatus (Goeze), A. vandalicus Ros., Exolygus pratensis L., E. rugulipennis Popp., Polymerus vulneratis Pz., P. cognatus Fb., Chlamydatus pullus Rt., Plagiognathus bipunctatus Rt., Platyporus dorsalis Rt., Camponotidea fieberi Rt., Grypocoris fieberi Dgl., Apion kitty F., Thrips tabaci Lindeman, Frankliniella occidentalis (Pergande), Schistocerca gregaria Forsk., Empoasca decipiens Paoli, E. fabae (Harris), Spodoptera exigua (Hübner), S. littoralis (Boisduval) Pieris rapae (L.) (Bingöl, 1978; Turkmen and Hıncal, 1984; Shebl et al., 2008). Apart from these types; Clover proboscis beetle, Hypera postica Gyllenhal and Sitona humeralis Stephens (Curculionidae), Gonioctena fornicata (Brüggemann) (Chrysomelidae) and Epicauta erythrocephala (Pallas) (Meloidae); Alfalfa seed capsid of the order Hemiptera, Adelphocoris lineolatus (Goeze) and Exolygus rugulipennis (Poppius) (Miridae), Spotted clover aphidi, Therioaghis

trifolii Monell, Acyrthosiphon pisum (Harris) and Aphis craccivora Koch (Aphididae); From Lepidoptera Nomophila noctuella Denis &. Schiffermüller (Crambidae), Agrotis ipsilon Hufnagel, Spodoptera exigua (Hübner) (Noctuidae); From Hymenoptera Bruchophagus roddi From Gussakovskiy (Eurytomidae) and Acarina Tetranychus Species such as spp. (Tetranychidae) cause economic damage to alfalfa (Çalışkaner and Özer, 1980; Turkmen and Hıncal, 1984; Tamer et al., 1997; Shebl et al., 2008; Gözüaçık and Atay, 2016; Gözüaçık and İreç, 2016; Blind, 2019; Gözüaçık et al., 2021). Among these species are the Clover proboscis beetle, Hypera postica (Gyllenhal, 1813) is the main pest of the clover plant. Apart from this type; Sitona humeralis Stephens (Curculionidae), Gonioctena fornicata (Brüggemann) (Chrysomelidae) and Epicauta erythrocephala (Pallas) (Meloidae); Alfalfa seed capsid from the order Hemiptera, Adelphocoris lineolatus (Goeze) and Exolygus rugulipennis (Poppius) (Miridae), Spotted clover aphidi, Therioaghis trifolii Monell (Aphididae); From Lepidoptera Nomophila noctuella Denis &. From Schiffermüller (Crambidae) and Hymenoptera Bruchophagus roddi Gussakovskiy (Eurytomidae) species also cause more damage to alfalfa (Çalışkaner and Özer, 1980; Turkmen and Hıncal, 1984; Tamer et al., 1997; Shebl et al., 2008; Gözüaçık and Atay, 2016; Gözüaçık and İreç, 2016; Blind, 2019; Gözüaçık et al., 2021). Although these cause damage at different stages of development of the plant, most of them are oligophagous species. While green manure plants are an advantage for harmful species with limited hosts, they can become disadvantageous for polyphagous species. These species can complete a period of their life here and pose a potential threat to other cultivated plants in the same habitat. However, these plants are called from the order Hymenoptera Andrina ovatula (Kirby), Anthophora Spp. Xylocopa Spp. Ceratina Spp. Halictus Spp. Apis mellifera L., Chalcidoma siculum, Osmia Spp. Megachile submucida Alfken, Megachile uniformis Mitchell Megachile mintusemina while attracting pollinator insects such as (Shebl et al., 2008), from insects that are predators of phytophagous species Coccinella septempunctata L., C. undecimpunctata (L.), Adonia variegata Goeze, Proyplaea             quatuordecimpunctata       (L.),         Coccinula

quatuordecimpustulata (L.), Deraeocoris serenus Dgl., Syrphus spp., Episyrphus balteatus (De Geer), Scaeva pyrastri (L.), Metasyrphus corollae F., Melanostoma mellinum L. Sphaerophoria rueppellii Wied, Nabis pseudoformis Rem., Aeolothrips intermedius Bagnall, A. collaris Priesner, Orius niger Wolf., O. laevigatus (Fieber), Scymnus flavicollis (Redtenbacher), S. rubromaculatus (Goeze), S. frontalis (Fabricius), Paederus alfierii Koch, Sphodromatis bioculata (L.), Eremiaphila savignyi Lefebvre, Mantis religiosa L., Chrysopa carnea (Stephens), Cueta variegata (Klug), Ischenura senegalensis (Rambur,), Crocothemis erythraea (Brullé) and Syrphus spp. (Erol and Karagöz, 1996; Atakan and Tunç, 2004; Shebl et al., 2008) and parasitoid insects such as Bathyplectes curculionis Thomsen, Anaphes sp. near leptoceras (Debauche), Mesochorus nigripes Ratz., Zoophthorus graculus Grav., Pteromalus semotus Walker, Bracon crocatus Shm., Chelonella nitens (Rhd.) (Türkmen and Hıncal, 1984; Goreat and Pricorp, 2017; Gözüaçık, 2019). As can be seen from the harmful and beneficial insect species given above, it is a storehouse of natural enemies that contribute to minimizing primary and secondary insect outbreaks not only in the alfalfa plant but also in the surrounding crops (Summers, 1998; Madeira et al., 2019 ).

When Brassicaceae species are used as green manure, they have a biofumigant effect against wireworms (Agriotes spp.) such as the mustard plant containing Glucosinylate  (Frost et al., 2002). In addition, it is stated that the radish plant is a very good trap plant for root and nematoids and biofumigant if applied to the soil as a green manure (Melakeberhan et al., 2008). Meagher et al. (2004)  reported that the use of Vigna unguiculata (L.) (cowpea) and Crotalaria juncea L. (sun hemp) plants as green manure against the Spodoptera frugiperda (Smith) pest  can reduce pest populations. Thoudam and Chhetry (2017), on the other hand,  stated that green manure application is more effective than chemical fertilizer in promoting resistance to insect pests as a result of their comparison with chemical fertilizer against Scirpophaga incertulas (Walker) and Nymphula depunctalis Guenee (Pyralidae: Lepidoptera),  two important pests of Colocasia esculenta Linn. plant as green manure in paddy plant  . While green manures create suitable habitats for forficula (Dermaptera: Forficulidae) and crickets (Orthoptera, Gryllidae), they can also host predator insects such as carabid (Carabidae) and staphylinid (Staphylinidae) (Coleoptera) in soil habitat.

• RESULT

After all;

• Green manure plants provide suitable habitat for ground beetles.
• It contributes to an increase in the diversity of entomopathogens in the soil, putting pressure on the pest population.
• Green manure crops diversify monoculture farmlands, attracting many beneficial insects.
• Green manure plants provide food (pollen, nectar) and alternative habitats for the adults of beneficial insects.
• When green manure plants are mixed into the soil, many pests living on them are damaged because they have not yet completed their development. However, beneficial insects on the plant can migrate to adjacent fields, supporting the beneficial insect population.
• Since no insecticides are applied to green manure plants, it contributes to the increase of beneficial insect diversity and population.
• It contributes to the healthy cultivation of the plant; Thanks to this, the plant becomes more tolerant of pests.
• The selection of green manure plants to be grown in the agroecosystem from plants that are not hosts of the dominant pests adversely affects the pest population.

CHAPTER 11

GREEN FERTILIZATION IN SUSTAINABLE AGRICULTURE

1. ENTRANCE

For any agricultural production system to be sustainable, green manure crops and/or green manure must be part of or the backbone of this system. Because green manure plants; They are important in sustainable agriculture due to nitrogen (N) fixation, nutrient supplementation, source of organic matter, improvement of the physico-chemical and biological structure of soils, protection of soil and water, suppression of weeds (Reddy, 2016). The inclusion of green manure or any organic fertilizer in agricultural soil reduces the application of chemical fertilizers while maintaining crop yield. For this reason, the application of legume green manure is a valuable application for agricultural ecosystem management.

This section summarizes the role and benefits of green manure in the agricultural and environmental ecosystem; The role of green manure crops in crop rotation systems in terms of increasing production is discussed.

• GREEN FERTILIZER-ENVIRONMENT RELATIONSHIP
  • The Effect of Green Manure on Greenhouse Gas Emissions

One of the main causes of global warming is the increase in the concentration of greenhouse gases in the atmosphere; In the greenhouse effect, carbon dioxide (CO2) gas is the most effective with 76.7%, followed by methane (CH4) with 14.3% and nitrous oxide (N2O) with 7.9% (Kuppusamy et al., 2016). Agricultural sector emissions in Turkey were determined as 68.0 million tons of CO2 equivalent (EQ) in 2019, an increase of 47.7% compared to 1990 and 4.1% compared to the previous year. The agricultural sector accounts for about 13.4% of total greenhouse gas emissions. Agriculture in Turkey

Share of CO2 emissions in the sector %                         While 0.3, N2O and CH4

emissions were 72.5% and 62.4%, respectively (Anonymous, 2022). Agricultural soils contribute to emissions of CH4 and N2O, the two most important greenhouse gases responsible for global warming (Das and Adhya, 2014). On a global scale, emissions from agriculture increased by approximately 50% between 1961 and 2019, reporting 5 Gt CO2eq ^year-1 (Tubiello, 2019). About 35% of global N2O emissions from the earth’s surface into the surrounding atmosphere come from agriculture (Kroeze et al., 1999). The source of N2O emissions in agricultural activities is the increased use of nitrogen fertilizers and animal manure production. The biological process in the soil, especially the events of nitrification and denitrification, also plays a major role in the release of N2O (Granli and Bøckman, 1994). Green manure application affects N2O emission by increasing microbial activity, which can affect both soil fertility and the internal cycle of carbon and nitrogen (Fang et al., 2019; Lv et al., 2020). Lei et al. (2022) found that green manures not only improve soil fertility and the biological properties of soils; At the same time, they emphasized that it can also reduce greenhouse gas emissions. In this sense, green manuring has been envisioned to be an effective and sustainable tool to increase the sequestration of atmospheric carbon dioxide in agricultural ecosystems (Jarecki et al., 2009; Mancinelli et al., 2010; Forte et al., 2017).

In a study conducted to determine the effect of different green manure (barley, hairy vetch and barley + hairy vetch mixture) applications on global warming potential (GWP) and greenhouse gas intensity (GHGI) (Lee et al., 2021); It has been reported that green manure significantly affects CO2 and N2O emissions, but not CH4, and green manure species such as hairy vetch, which have high biomass production and carbon input, increase the net ecosystem carbon budget (NECB) and reduce net GWP and greenhouse gas intensity. The results of this research, in which the corn plant was grown in the same area after green manure; It has been shown that a green manure system, such as a mixture of downy vetch and downy vetch+barley, can reduce net CO2 emissions per corn grain production as well as nitrogen fertilization with urea in terms of economic viability and environmental protection. The researchers also found that strategies to reduce greenhouse gas emissions in cornfields; They emphasized that it should be aimed at high biomass production, carbon input and the cultivation of green manure types aimed at increasing the biomass yield of the next crop.

In temperate zone countries such as Korea and Japan, it is highly recommended to grow winter cover crops as green manure in paddy soils (Kim et al., 2012). Similarly, in southern China, the use of winter green manures in paddy soil to maintain soil fertility is a traditional and effective cultivation model (Gao et al., 2018). In these countries, where paddy cultivation is intense,  leguminous plant species such as Astragalus sinica, Crotalaria juncea and Sesbania aculeate are widely grown for green manure in the winter intermediate period and/or in fallow years  . Many studies have shown that plant residue applications such as green manure maintain soil quality and increase paddy productivity in paddy fields (Choi et al., 2014; Haefele et al., 2014; Gao et al., 2017; Gao et al., 2018; Nandan et al., 2019). However, concerns about CH4 emissions from paddy fields after the application of green manure are still important aspects of the issue that need to be investigated today. Because, paddy land is the main source of greenhouse gas emissions and accounts for about 10-12% of the total global agricultural emission sources (Liu et al., 2021).

The ratio of soil carbon to nitrogen (C/N) is an important parameter affecting CH4 production in submerged paddy soil; When the C content and C/N ratio of the material mixed into the paddy soil decreases, methane production and emission decreases (Devevre and Horwath, 2000).

In a study conducted in Korea, it was revealed that the application of 10 t/ha of green manure (Astragalus sinicus L.) in monoculture paddy cultivation  may be an effective application level in maintaining paddy productivity without increasing CH4 emission compared to NPK fertilization (Lee et al., 2010).

In  a study in which Astragalus sinicus and annual grass plant were grown as green manure in the winter interim period in paddy-paddy cultivation  after paddy harvest; green manure applications with A. sinicus plant with low C/N ratio  were recommended both to increase soil and paddy productivity and to minimize the impact of CH4 emissions (Kim et al., 2012). Again, similar findings were obtained in another study conducted in paddy fields;  It has  been emphasized that the green manure-paddy system, which includes a green manure plant with a low C/N ratio such as Astragalus, may be a more desirable production system than the monoculture paddy system to reduce the total global warming potential per grain yield and improve paddy productivity (Kim et al., 2013).

In a study in which two types of green manure, alfalfa (Medicago sativa L.) and fodder pod (Vicia faba L.) and two nitrogen fertilization levels (0 and 200 kg/ha) were applied alone and in combination in paddy fields; It was determined that CH4 and N2O emissions increased by 50.77% and 36.11%, 30.70% and 75.04% respectively compared to nitrogen fertilizer application in N+feed pod and N+alfalfa applications. In the same study, NECB and mass of soil total carbon change (MSTC) were the highest in N+alfalfa (with a low C/N); The highest value in GHGI was determined in the application of N+feed pods (with a high C/N ratio). According to these results, green manures with low C/N ratio have even higher paddy grain yield with increased NECB and MSTC; In addition, it has been reported that high grain yield is obtained from the application of green manures with high C/N ratio, but greenhouse gas emissions also increase. Researchers found this situation; They explained that the higher C/N ratio of feed pods results in a slower decomposition rate, which leads to a lower carbon mineralization than alfalfa, providing more carbon substrate for CH4 production (Gao et al., 2016).

In a study analyzing the effects of the paddy-paddy-green manure cultivation system on paddy yield and greenhouse gas emissions in both paddy and winter-green manure seasons (Raheem et al., 2019); Annual applications of grass-paddy-paddy, geven-paddy-paddy and rapeseed-paddy-paddy, fallow-paddy-paddy were examined. According to the results of this research, higher CH4 emissions and global warming potential were determined in the “grass-paddy-paddy” system, which includes grass green manure, which provides significantly higher biomass and has a higher C/N ratio compared to geven and rapeseed, compared to the “fallow-paddy-paddy” system; on the other hand, the system containing geven green manure, which has a low C/N (11.13), reduced CH4 emissions and global warming potential compared to fallow. In the same study, it was reported that green manure applications reduced N2O emissions compared to fallow-paddy-paddy, although annual cumulative N2O emissions were insignificant across all processes. The researchers found that geven with a low C/N ratio increased rice yields and reduced greenhouse gas emissions; In terms of annual yield scale GWP, they reported that the geven-paddy-paddy system can be recommended for long-term yield sustainability and environmentally friendly paddy production.

Zhong et al. (2021) reported that the addition of green manure (Astragalus sinicus L.) in the paddy-paddy system  reduced CH4 emissions due to the decrease in soil C/N ratio and increased soil permeability. Similar reports were reported by Zhou et al. (2020); Researchers have stated that legume green manure can reduce CH4 emissions.

Excessive application of chemical fertilizers results in significant N2O emissions (Zhou et al., 2022). In this sense, conscious application of nitrogen fertilizers and irrigation can reduce the potential for global warming by reducing greenhouse gas emissions (Anonymous, 2007). For this reason, it is a fact that in paddy agriculture, which has a high demand for water and fertilizer, in addition to the implementation of good water management, the dissemination of the green manure system that reduces the use of nitrogen fertilizers and the improvement of these areas with green fertilizers will contribute to the reduction of global warming.

In a study conducted in citrus orchards, organic fertilizer or green manure (Vicia villosa Roth.var. glabrescens Koch) has been determined to maintain citrus yields and reduce cumulative N2O emissions compared to chemical fertilization. It has been stated that this system, which reduces the use of chemical fertilizers, is an extremely important fertilizer management strategy in terms of sustainable productivity and environmental protection in citrus orchards (Zhou et al., 2022).

In green manure applications, annual cumulative CH4 and N2O emissions vary depending on the biomass and C/N ratio of green manure plants. In other words; Differences in greenhouse gas emissions between green manure applications are significantly influenced by both the biomass and the C/N ratio of green manure plants (Gao et al., 2016; Raheem et al., 2019).

In the light of this information in the literature, it is possible to say that green manure can reduce greenhouse gas emissions from crop growing systems in general. This process will vary according to the type and type of green manure, application time, ecological conditions and soil factors (soil pH, nutrient and microorganism level, etc.).

However, it has also been stated that mixing green manure plants into field soil can increase greenhouse gas emissions such as CO2, CH4, and N2O during mineralization (Lee et al., 2021). In some studies in corn farming, green manure has been reported to increase N2O emissions from the soil (Gomes et al., 2009; Alluvione et al., 2010). This is also thought to be related to the C/N ratio of green manure. As a matter of fact, Dalal et al. (2008) reported that the high C/N ratio during the incorporation of plant residues into the soil can increase the concentration of unstable C in the soil and subsequently stimulate the production of CH4 by methanogens under anaerobic conditions. Similar statements have been reported by Conrad (2007), Yang et al. (2010) and Li et al. (2013); The researchers reported that CH4 production can be encouraged during paddy production in irrigated conditions in paddy soil where green manure is applied. However, despite this, little is known about it; Therefore, much more work needs to be done.

The application of green manure has been good productivity management for crop growth and soil quality; however, GHGI and its effect on NECB are not well understood (Gao et al., 2016).

• The Role of Green Manure in Reducing Soil Pollution and Improving Soil Health

The increase in the use of chemical fertilizers, herbicides, pesticides to increase agricultural productivity, and the discharge of solid and liquid wastes with urbanization increase the pollution in agricultural soils. In addition, agricultural production technology based on unconscious chemical fertilization to obtain high yield and quality products in agricultural production also causes serious losses in organic matter and plant nutrients in the soil. This significantly reduces soil health. The application of organic fertilizers to contaminated soil is a practical method in order to improve or mitigate soil pollution and maintain soil fertility, as well as provide nutrients for plant growth. Due to increasing concerns about environmental pollution and soil health, attention and research have turned to green manure, which is an important component of organic fertilizers. Green manuring is a good option to restore organic matter in the soil and increase the plant nutrient status of soils. However, there is little scrutiny on the use of green manure systems on soil contamination and soil health issues. In addition, phytoremediation, which is a plant-based strategy to reduce or eliminate soil and water pollution, is another agricultural practice.

Green manure application; improves levels of organic carbon, total N, and upable phosphorus (P) in soil compared to soil treated with inorganic fertilizer (Bhardwaj and Dev, 1985; Hoque et al., 2016), by improving soil organic matter with the aim of improving soil quality

increases nutrient turnover (Egodawatta et al., 2011). Plant biomass added to the soil by green manure improves the soil carbon stock (Song et al., 2021), increases the enzyme activity of soils (Özyazıcı et al., 2010; Driver et al., 2014). All these effects that occur with green manuring are the most obvious indicators of soil health. Although it varies according to the plant species used, green manures contain a large amount of macro and micronutrients. Green manures, especially those using legumes, contain relatively more N and have a low C/N ratio. So much so that green manures, which consist of leguminous plants with abundant vegetative parts buried under the ground before flowering, act as N fertilizers. In addition, with green manure, the breakdown of green manure plants in the soil and the contribution of nitrogen to the soil and the next product due to the breakdown, that is, the supply of N from green manure, continues for a much longer period than chemical fertilizer. For this reason, agricultural systems in which green manure is involved are systems in which soil health is maintained for a long time.

Fertilization is one of the methods used to increase the yield from the unit area in agricultural areas. In today’s world, where the need for food increases due to the population growth rate, the consumption of chemical fertilizers in agricultural production increases at almost the same rate. In this sense, fertilizers containing N and P are in the lead; Excessive and unconscious fertilization causes both soil and water pollution. Nitrate that mixes with groundwater and/or accumulates in the plant with excessive and intense nitrogen fertilization is one of the leading pollutants. In addition, cadmium (Cd) pollution caused by phosphorus fertilizers is the most important part of soil pollution. In this sense, green manure application, in which legumes with high biological N fixation capacity are used, and agricultural systems in which this application is involved, reduce the use of nitrogen fertilizers and ensure that many macro and micronutrients necessary for plants become suitable in the soil. There is no doubt that this feature of green manure, in its very simple form, will make significant contributions to the reduction of soil pollution and even soil degradation. As a matter of fact, Naher et al. (2020) emphasized that one of the most reported benefits of green manure is its contribution to the nutrition of agricultural crops, which can lead to a reduction in environmental pollution. It is a completely environmentally friendly system with biological N fixation through the application of green manure, as well as the N gained by the decomposition of green manure.

Long-term application of green manure has been reported to minimize hazardous substances such as iron contamination in paddy soils (Gao et al., 2017).

Sesbania rostrata is a popular leguminous green manure plant that improves soil health and paddy fertility with its high biomass (5-6 tons of dry biomass) and biological N fixation properties, increasing paddy yield by 9-11% compared to chemical fertilizer. A large amount of nitrogen fertilizer is needed to get high yields in paddy.  It is reported that S. rostrata can supplement at least 50% of the chemical N for paddy production and will save a significant amount of global energy by ensuring food security. For this reason, it has been stated that the large-scale use of S. rostrata for paddy production can reduce the need for chemical N and the spread of reactive nitrogen (Nr) to the environment and environmental pollution problems (Naher et al., 2020).

In the study, it was determined that the application of green manure to paddy soil contaminated with Cd increased the concentration of dissolved organic carbon (DOC) in soil solutions, which tended to decrease paddy growth due to the decomposition of DOC by microbial activities. In addition, due to the increase in the bioavailability and mobility of cadmium with the addition of green manure to the soil, it facilitates the uptake of cadmium by the paddy plant and its mixing with the ground water; therefore, it is likely that paddy fields contaminated with Cd are likely to produce rice containing a higher concentration of Cd, posing a risk of water pollution and, consequently, threatening human health through the consumption of contaminated rice and water; therefore, it has been reported that caution should be exercised in the use of organic fertilizers to improve soil fertility in practice (Wang and Zhou, 2017).

It is possible to decontaminate the soil with green manure, which is one of the many pesticides used for agricultural control and contaminated in the soil.

Mitra and Raghu (1988) reported that the application of green manure (leaves of Gliricidia sepium) reduced the persistence of the highly toxic insecticide DDT (Dichloro Diphenyl Trichloroethane).

Tebuthiuron is a herbicide that, as a result of its frequent use, can cause serious environmental effects such as long-term permanent effects on the soil and possibly contamination of groundwater. According to the results of a study examining the phytoremediation of soils exposed to this herbicide  with Cajanus cajan, Canavalia ensiformes, Dolichos lablab, Pannisetum glaucum, Estizolobium deeringianum, Estizolobium aterrimum and Lupinus albus plants; When 1.0 kg/ha of tebuthiuron is applied, C. ensiformesIt was determined that none of the evaluated species developed in soil that received the highest dose of tebuthiuron (1.5 kg/ha), giving the best phytoremediation results (Pires et al., 2005).

 In a study evaluating the potential for improvement of sulfentrazone herbicide with green manure species such as Crotalaria juncea, Canavalia ensiformis, Cajanus cajan and Cajanus cajan dwarf, Crotalaria juncea was found to be the most effective species in decontamination of sulfentrazone in soil (Madalão et al., 2012).

Reports on the use of green manures such as Canavalia ensiformis (L.) DC and Crotalaria juncea L. indicate that they have significant potential in removing herbicides such as sulfentrasone from the soil (Oliveira et al., 2014; Belo et al., 2016; Ferraço et al., 2017). Crotalaria juncea and Crotalaria spectabilis have been reported to be tolerant to glyphosate, methylsufuron, and 2,4-D herbicides in mixture with glyphosate (Concenço and Silva, 2015).

da Silva Teofilo et al. (2020), Canavalia ensiformes (L.) DC., Stilizobium aterrimum L. and Lupinus albus L. green manure species are tolerant to hexazinone and have remedial effects in removing residues of this herbicide from the soil.

In a study examining the phytoremediation of soils contaminated with quinclorac and tebuthiuron, which are among the residue herbicides that can remain in the soil longer than the harvest season, using Crotalaria spectabilis, Canavalia ensiformis, Stizolobium aterrimum and Lupinus albus green manure plants; These four green manure plants also have the ability to remediate soils contaminated with quinclorac and tebuthiuron. It has  been reported that Canavalia ensiformis is more effective in improving tebuthiuron-treated soil compared to other plants (Mendes et al., 2021).

The fact that some green manure plants are tolerant to herbicides may be a promising indicator for their use in phytoremediation (Schultze-Kraft et al., 2018).

The application of green manure, which increases soil organic matter, can be an economical option for waste disposal. In general, different organic additives have different effects on wastes due to the differences in chemical reactions that occur between organic substances and wastes (Ai et al., 2020). The application of green manure increases the organic matter of the soil and the amount of N; this, in turn, means a significant supply of N for the next product. Therefore, green manuring can be an economical option for waste rehabilitation.

Ai et al. (2020) reported that the application of green manure (Medicago sativa L.) would be an effective approach to improve the ecological environment of gold waste.

• EVALUATION OF THE ROLE OF GREEN FERTILIZATION IN CROP ROTATION

The decrease in the organic matter content of the soils and the negative changes in the soil structure can be explained by monoculture agriculture and/or not giving the necessary importance to the crop rotation or including fewer plant species in the planting rotation. Leguminous green manure plants’  unique ability to sequester atmospheric nitrogen using Rhizobium bacteria in their roots, as well as their ability to produce biomass and nutrients, has made them one of the most studied crop groups in agricultural ecosystems worldwide (Pál & Zsombik, 2022). Including legume plants for green manure in the sowing rotation provides significant benefits in terms of both soil fertility and increasing agricultural productivity/vegetative productivity (Özyazıcı et al., 1995). The inclusion of green manure crops in crop rotation and crop rotation and green manure is also a way to maintain soil health and quality.

Inclusion of spring green manure with common vetch (Vicia sativa L.) in the crop rotation; It has been reported that it is an alternative system to recycle the nutrients removed from the soil with the previous crop, to reduce the need for inputs and carbon footprint, to protect soils and to increase soil organic matter content (Pál and Zsombik, 2022).

Including green manure in the crop rotation, organic matter, nitrogen, phosphorus, potassium (K), calcium, magnesium and various trace elements in the soil increase at a certain rate after the decomposition of green manure (Li et al., 2015; Yang et al., 2018) and thus increases the yield and improves the quality of the successor crop in rotation due to the improvement of soil fertility (Zhao et al., 2015). In the “green manure-corn-wheat” rotation system, which is frequently applied in the Çarşamba Plain located in the coastal zone of Turkey, it is possible to grow fodder pods (Vicia faba  L.) as a winter intermediate for green fertilization; In the application of green manure with feed pods, it has improved the biological (Driver et al., 2014), physical and chemical (Özyazıcı and Özdemir, 2013) properties of the soils and provided significant increases in corn and wheat yield and quality in crop rotation (Özyazıcı et al., 2009). In the studies carried out in China, paddy-Lolium multiflorum Lam., paddy-Astragalus sinicus L. and paddy-fallow system were handled and Lolium and Astragalus species were used as green manure in rotation, in the rotation of legume green manure (paddy- Astragalus sinicus L.) soil organic carbon and total N values were significantly higher than other rotation pairs, and improvement of paddy soils with continuous green manure during crop rotation increased soil organic carbon compared to control (Hou et al., 2022); legume green manure significantly (7.71%) increased the yield of cereal crops in grain rotation (Liang et al., 2022); that paddy-green manure (Vicia faba L.) rotation has a stronger positive effect on the physico-chemical and microbial properties of the soil (Bai et al., 2022); According to the paddy-paddy cultivation system, it has been reported that paddy-green manure-paddy rotation as winter green manure (Astragalus sinicus L.) is an effective approach for the substitution of chemical fertilizer, and the crop rotation system with green manure increases the sustainability of yield and soil quality (Zhang et al., 2023). Ram et al. (2022) emphasized that the inclusion of green manure in crop rotations has a positive effect on the physical properties of the soil and improves soil health. Sharma et al. (2022) stated that green manure application should be recommended and disseminated in the idle period between wheat harvest and paddy cultivation for the sustainability of the paddy-wheat crop rotation system, which is threatened by the emergence of new problems of climate change caused by large-scale burning of stubble residues and low nutrient use efficiency and deterioration of soil health.

Soil microorganisms and their life processes serve as a vital factor influencing the long-term development of the agricultural ecosystem (Bending et al., 2004). Therefore, the effects of green manure rotations on the microbial biomass and enzyme activity of soils are of great importance. Lupwayi et al. (1998) found that microbial diversity was significantly higher in wheat that came after meadow tricrony green manure or peas than in wheat that came after wheat (perpetual wheat) or summer fallow; They reported that legume-based crop rotations promote the diversity of soil microbial communities and may affect the sustainability of agroecosystems. In another study; Compared to paddy-paddy-winter fallow, it has been reported that more abundant bacterial communities are formed in paddy roots in the paddy-paddy-Astragalus  (green manure) rotation system, and the rotation system in which green manure is located is richer in terms of endophytic bacteria diversity (Zhang et al., 2013). Italian grass (Lolium multiflorum L.) -It  has been reported that the application of green manure in the paddy (Oryza sativa L.) rotation system facilitates paddy growth by improving the composition and diversity of bacterial communities and soil fertility (He et al., 2020).

Green manuring with leguminous forage crops in crop rotation can increase the organic matter content of soils and improve soil water content compared to fallow. As a matter of fact, it has been determined that soils treated with pure vetch green manure during winter wheat and corn crop rotation have significantly higher moisture content than soils treated with pure oats and oat-vetch mixture (Wang et al., 2020).

• THE ROLE OF GREEN FERTILIZATION IN ORGANIC AGRICULTURE

Organic farming is an agricultural strategy to produce healthy food, soil, plants, the environment, and other biotic factors (Bista and Dahal, 2018). Organic farming, sometimes called biological or ecological farming; It aims to crop rotation, manage pests naturally, increase crop diversity, and improve the soil with the addition of animal manures, compost, and green manure (Reganold and Wachter, 2016). In this respect, the use of fertilizers other than organic fertilizers is prohibited in organic agriculture. As mentioned in the previous sections, many studies have shown that legumes used as green manure with biological N fixation capacity can provide enough biological N to replace all amounts of synthetic nitrogen fertilizers in use. Therefore, leguminous green manure plants are important in organic farming systems due to their ability to accumulate N.

Intensive research on organic agriculture is not only in terms of obtaining healthy products; At the same time, it is of great importance in terms of improving soil quality and health. For this reason, every practice that improves soil health concerns organic farming. Green manure is one of these applications.

In the organic farming system, green manures are the most important source of phosphorus that can be taken by plants in the soil.

Especially legume plants, which are used as green manure, accumulate a significant amount of P in their bodies during their growth. During the decomposition of green manure plants in the soil, basic nutrients such as N, P and K in the plant structure pass into the soil structure and these elements are recycled (Sharma and Ghosh, 2000; Cavigelli and Thien, 2003; Singh et al., 2007; Cypress and Kalpana, 2009). Increased uptake of phosphorus in the soil; It is explained by the increase in organic carbon in the soil with the breakdown of green manures, the corresponding decrease in soil pH, and ultimately the low pH also reduces phosphate fixation (Dey and Nath, 2015). Green manure converts phosphorus fixed in the soil into absorbable forms, increasing the P uptake of subsequent crops (Cavigelli and Thien, 2003). In an organically managed system,

Considering that the mineralization of organic phosphorus present in the soil is the main source of phosphorus (Bista and Dahal, 2018), the importance of green manure in organic agriculture can be understood much more clearly. As a matter of fact, Xavier et al. (2009) report that the risks of P loss should be considered in organically managed areas and that green manure should be included for better management of organic farming, especially in sandy soils.

Soybeans (Gylcine max L. Merr.), fodder cowpea (Vigna sinensis L.) and corn (Zea mays L.) were used as summer green manure, where the effects of green manure and green manure + chicken manure applications on the yield and fruit quality of organic tomatoes grown in the greenhouse were examined.) in a study using ; It has been suggested that green manure plants increase the amount of organic matter, total N, P and K in the soil, and that green manures should be included in production programs as an alternative form of fertilization because they are sensitive to human health and the environment (Duyar, 2014).

In organic production systems, the activity of soils, especially the microbial population, is important in order to obtain high yield and quality products.

It has been reported that the highest values in terms of total organic carbon, humic matter, microbial biomass, azotobacter count, protease activity are obtained from green manure applications in organic vineyard soils where barley + vetch and broad bean + vetch green manures and farm manure applications are located, and green manure is the application that stimulates the microbiological activity in the soil the most in organic vineyard cultivation (Çengel et al., 2009).

When broad beans (Vicia faba  L.) are used as green manure in the organic tomato production system, it has been reported that green manure can be done after fresh pods are collected, so that additional income can be provided to the producer on the one hand, and on the other hand, soil properties can be improved with green manure for the next crop. As a matter of fact, in the same study, it was reported that soil organic matter and soil microbial activity increased with the use of green manure and that green manure contributed to the improvement in tomato yield (Alagöz et al., 2020).

It has been reported that the practices including green manure give the best results in the organic production of different products in Turkey, improving the yield and quality of the products.

For example; Green manure + farm manure + humic acid + foliar fertilizer application to organic strawberry growers in Ankara ecological conditions (Polat and Çelik, 2008), vegetable waste compost at the rate of 40 tons/ha together with green manure in oil pepper produced in the open according to organic farming principles (Kır and Mordoğan, 2010), commercial organic fertilizer application together with green fertilizers + farm manure application for organic apricot cultivation in Malatya (Şahin et al.,  2011), green manure + organic fertilizer + humic acid + farm manure combination application (Şahin and Atay, 2018) has been recommended in terms of soil characteristics and sapling development in organic apricot sapling cultivation.

It has been reported that in pistachio cultivation in the Southeastern Anatolia Region, green manure application stands out in terms of yield and some quality characteristics, the highest net income is received from green manure application, and this result is effective in terms of net income due to the low production cost of green manure application and the high price of organic product (Karadağ et al., 2011). It has been observed that the combination of green manure + cattle manure gives the best results in terms of yield in organic Bursa black fig cultivation in Yalova conditions (Soyergin et al., 2011). In the organic cultivation of the Hicaznar pomegranate variety, which is widely grown in Turkey and has high export potential, the highest yield and quality are from the application of green manure + cattle manure with traditional application, respectively; It was determined that the highest net profit was obtained from the application of green manure + cattle manure (Yazıcı et al., 2011). In organic lettuce cultivation, the highest lettuce yield (71.8 and 76.5 t/ha) was obtained by green manure + farm manure application (Caliskan et al., 2014).  It has been shown that green manure (Vicia sativa L.) can be used as an alternative to farm manure in organic cowpea cultivation  (Toy and Ünlü, 2015).

It has been reported that in the rotation of organic potatoes (Solanum tuberosum L.) in Eastern Canada  , green manures consisting of annual legumes can be used to meet the N requirement of potatoes and this practice maintains soil quality in organic potato rotations (Sharifi et al., 2014).

• result

Green fertilizers or green fertilization, apart from their known benefits, are the main element of sustainable agriculture because they play an important role in reducing soil pollution and greenhouse gas emissions and are the most important component of October and organic farming systems. In this century, when both human and soil health is decreasing every day and concepts such as food security are frequently used, the re-implementation and dissemination of environmentally friendly agricultural systems such as green fertilization – the oldest-known-but the value of which is not understood – should be one of the most important agricultural goals.