The un-decomposed plants prepare the ground for cash crops by slowly releasing nutrients like nitrogen into the soil.

Depending on the species of cover crop grown, the amount of nitrogen released into the soil lies between 40 and 200 pounds per acre.

This additional decomposition also allows for the re-incorporation of nutrients that are found in the soil in a particular form such as nitrogen (N), potassium (K), phosphorus (P), calcium (Ca), magnesium (Mg), and sulfur (S).

[5] The increased percentage of organic matter (biomass) improves water infiltration and 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.

[8] Incorporation of green manures into a farming system can drastically reduce the need for additional products such as supplemental fertilizers and pesticides.

Limitations to consider in the use of green manure are time, energy, and resources (monetary and natural) required to successfully grow and utilize these cover crops.

Green manure is broken down into plant nutrient components by heterotrophic bacteria that consumes organic matter.

[9] Legumes, 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] Many green manures are planted in autumn or winter to cover the ground before spring or summer sowing.

[3] Chinese agricultural texts dating back hundreds of years refer to the importance of grasses and weeds in providing nutrients for farm soil.

[citation needed] Managing green manure improperly or without additional chemical inputs may limit crop production.