Editing Green manure (section)

==Nutrient release==
Green manure is broken down into plant nutrient components by [[heterotrophic]] bacteria that consumes organic matter. Warmth and moisture contribute to this process, similar to creating [[compost]] fertilizer. The plant matter releases large amounts of carbon dioxide and weak acids that react with insoluble soil minerals to release beneficial nutrients. Soils that are high in [[calcium]] minerals, for example, can be given green manure to generate a higher [[phosphate]] content in the soil, which in turn acts as a fertilizer.<ref name="Lawrence 1980 145">{{cite book|last=Lawrence|first=James|title=The Harrowsmith Reader, Volume II|year=1980|publisher=Camden House Publishing Ltd.|isbn=0920656102|pages=145}}</ref>

{{main|Carbon-to-nitrogen ratio}}
The ratio of carbon to [[nitrogen]] in a plant is a crucial factor to consider, since it will impact the nutrient content of the soil and may starve a crop of nitrogen, if the incorrect plants are used to make green manure. The ratio of carbon to nitrogen will differ from species to species, and depending upon the age of the plant. The ratio is referred to as C:N. The value of N is always one, whereas the value of carbon or carbohydrates is expressed in a value of about 10 up to 90; the ratio must be less than 30:1 to prevent the manure bacteria from depleting existing nitrogen in the soil. [[Rhizobium]] are soil organisms that interact with green manure to retain atmospheric nitrogen in the soil.<ref>{{cite book|last=Lawrence|first=James|title=The Harrowsmith Reader, Volume II|year=1980|publisher=Camden House Publishing Ltd.|isbn=0920656102|pages=146}}</ref> [[Legume]]s, such as beans, alfalfa, clover and lupines, have root systems rich in rhizobium, often making them the preferred source of green manure material.{{Citation needed|date=February 2021}}