In agriculture, a green manure is a type of cover crop grown primarily to add nutrients and organic matter to the soil. Typically, a green manure crop is grown for a specific period, and then plowed under and incorporated into the soil. Green manures usually perform multiple functions, that include soil improvement and soil protection: Broadly defined, a cover crop is any annual, biennial, or perennial plant grown as a monoculture (one crop type grown together) or polyculture (multiple crop types grown together), to improve any number of conditions associated with sustainable agriculture. ... Link title {{portal|Food} A nutrient is either a chemical element or compound used in an organisms metabolism or physiology. ... This article does not cite any references or sources. ... Loess field in Germany Surface-water-gley developed in glacial till, Northern Ireland Technically, soil forms the pedosphere: the interface between the lithosphere (rocky part of the planet) and the biosphere, atmosphere, and hydrosphere. ... For the constellation known as The Plough see Ursa Major. ...

• Leguminous green manures such as clover and vetch contain nitrogen-fixing symbiotic bacteria in root nodules that fix atmospheric nitrogen in a form that plants can use.
• Green manures increase the percentage of organic matter (biomass) in the soil, thereby improving water retention, aeration, and other soil characteristics.
• The root systems of some varieties of green manure grow deep in the soil and bring up nutrient resources unavailable to shallower-rooted crops.
• Common cover crop functions of weed suppression and prevention of soil erosion and compaction are often also taken into account when selecting and using green manures.
• Some green manure crops, when allowed to flower, provide forage for pollinating insects.

Historically, the practice of green manuring can be traced back to the fallow cycle of crop rotation, which was used to allow soils to recover. Varieties of soybean seeds, a popular legume A flowering legume The term legume has two closely related meanings in botany, a situation encountered with many botanical common names of useful plants whereby an applied name can refer to either the plant itself, or to the edible fruit (or useful part). ... Species See text Wikimedia Commons has media related to: Trifolium Clover (Trifolium) is a genus of about 300 species of plants in the pea family Fabaceae. ... Binomial name Vicia sativa Vetch or tare is a nitrogen fixing leguminous plant. ... Nitrogen fixation is the process by which nitrogen is taken from its relatively inert molecular form (N2) in the atmosphere and converted into nitrogen compounds (such as, notably, ammonia, nitrate and nitrogen dioxide)[1] useful for other chemical processes. ... Common Clownfish (Amphiprion ocellaris) in their Magnificent Sea Anemone (Heteractis magnifica) home. ... Phyla Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ... Root nodules occur on the roots of plants that associate with symbiotic bacteria. ... See biomass (ecology) for the use of the term in ecology, where it refers to the cumulation of living matter Switchgrass, a tough plant used in the biofuel industry in the United States Rice chaff. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... ROOT is an object-oriented software package developed by CERN. It was originally designed for particle physics data analysis and contains several features specific to this field, but it is also commonly used in other applications such as astronomy and data mining. ... Yellow starthistle, a thistle native to southern Europe and the Middle East that is an invasive weed in parts of North America. ... Severe soil erosion in a wheat field near Washington State University, USA. For erosion as an operation of Mathematical morphology, see Erosion (morphology) Erosion is displacement of solids (soil, mud, rock and other particles) by the agents of ocean currents, wind, water, or ice by downward or down-slope movement... Look up flower in Wiktionary, the free dictionary. ... Forage is the herbaceous plant material (mainly grasses and legumes) eaten by grazing animals. ... Orders Subclass Apterygota Archaeognatha (bristletails) Thysanura (silverfish) Monura - extinct Subclass Pterygota Infraclass Paleoptera (may be paraphyletic) Ephemeroptera (mayflies) Palaeodictyoptera - extinct Megasecoptera - extinct Archodonata - extinct Diaphanopterodea - extinct Protodonata - extinct Odonata (dragonflies and damselflies) Infraclass Neoptera Superorder Exopterygota Caloneurodea - extinct Titanoptera - extinct Protorthoptera - extinct Grylloblattodea (ice-crawlers) Mantophasmatodea (gladiators) Plecoptera (stoneflies) Embioptera... Growing the same crop repeatedly in the same place eventually depletes the soil of various nutrients. ... Satellite image of circular crop fields in Haskell County, Kansas in late June 2001. ...

Green manure crops

• Winter cover crops such as oats or rye have long been used as green manures.
• Mustard
• Clover
• Fenugreek
• Lupin
• Sunn hemp, a tropical legume
• Vetch or Winter tares
• Winter field beans
• Alfalfa, which sends roots deep to bring nutrients to the surface.
• Buckwheat is a rapidly growing green manure in temperate regions.
• Ferns of the genus Azolla have been used as a green manure in southeast Asia.
• Velvet Bean (Mucuna pruriens) Common in the southern US during the early part of the 20th century, before being replaced by soybeans. Popular today in most tropical countries, especially in Central America where it is the main green manure used in Slash/Mulch farming practices.

Binomial name Avena sativa Carolus Linnaeus (1753) The Oat (Avena sativa) is a species of cereal grain, and the seeds of this plant. ... Binomial name Secale cereale M.Bieb. ... Species See text The mustards are several plant species in the genus Brassica whose proverbially tiny mustard seeds are used as a spice and, by grinding and mixing them with water, vinegar or other liquids, are turned into a condiment also known as mustard. ... Species See text Wikimedia Commons has media related to: Trifolium Clover (Trifolium) is a genus of about 300 species of plants in the pea family Fabaceae. ... Binomial name Trigonella foenum-graecum L. Fenugreek (Trigonella foenum-graecum) belongs to the family Fabaceae. ... Species 150-200 species, including: Lupinus albus Lupinus angustifolius Lupinus luteus Lupinus albifrons Lupinus arboreus Lupinus arizonicus Lupinus bicolor Lupinus chamissonis Lupinus diffusus Lupinus excubitus Lupinus formosus Lupinus longifolius Lupinus microcarpus Lupinus mutabilis Lupinus nanus Lupinus nootkatensis Lupinus perennis Lupinus polyphyllus Lupinus sparsiflorus Lupinus sulphureus Lupinus texensis Lupinus tidestromii Lupinus... Vicia sativa leucosperma Common name: Winter tares Family: Leguminosae Author: Ser. ... Binomial name Medicago sativa L. Subspecies subsp. ... Binomial name Fagopyrum esculentum Moench Common buckwheat (Fagopyrum esculentum) is a plant in the genus Fagopyrum (sometimes merged into genus Polygonum) in the family Polygonaceae. ... Species Azolla caroliniana Willd. ... World map showing the location of Asia. ...

Green manures in organic farming

Organic farming relies on soil health and cycling of nutrients through the soil using natural processes. Green manures perform the vital function of fertilization, in concert with the addition of animal manures if those are used. Organic cultivation of mixed vegetables in Capay, California. ... For other uses, see Animal (disambiguation). ...

See also

• Fertilizer
• Organic gardening
• Category:Soil improvers

Spreading manure, an organic fertilizer Fertilizers (also spelled fertilisers) are compounds given to plants to promote growth; they are usually applied either via the soil, for uptake by plant roots, or by foliar feeding, for uptake through leaves. ... It has been suggested that this article or section be merged with Organic horticulture. ...

External links

• Overview of cover crops and green manures
• Using green manure to grow rice [1]
• University of California cover crops database