绿肥是指主要用作肥料的栽培植物。其以新鲜植物体就地翻压,或沤、堆制后异地施用。绿肥多为豆科植物,也有禾本科和十字花科植物。由于复种指数和单产不断提高,土壤营养释放利用很快但又难以及时补充。种植绿肥可以较快地将有机质、矿物质返还给土壤,平衡补充营养。豆科绿肥植物有固定空气中游离氮的能力,可以利用生物固氮作用增加土壤氮素,而且根系发达,能吸收利用土壤耕层以下的一般作物不易利用的养分,将其转移、集中到地上部,待绿肥翻耕腐解 Green manure is a cultivated plant that is primarily used as a fertilizer. Its fresh plant body pressure, or 沤, piled up after the remote application. Green manure mostly legumes, but also grasses and cruciferous plants. As the multiple cropping index and yield continue to increase, soil nutrient release quickly but difficult to replenish. Green manure can be quickly converted to organic matter, minerals returned to the soil, balanced nutritional supplements. Leguminous green manure plants have the ability to fix free nitrogen in the air and can use biological nitrogen fixation to increase soil nitrogen and have developed root systems that can absorb and utilize nutrients that are not readily available from the general crop below the soil layers and transfer them to above ground , Until the green fertilizer plowing decomposition