绿肥作物,特别是豆科绿肥,不仅是土壤有机质的重要来源,更是作物氮素的良好给源。绿肥的后一作用,历来受到人们的重视。许多研究者研究了绿肥中氮素对当季作物的有效性以及影响氮素有效性的因素。已经知道,除土壤性质和作物种类外,绿肥作物的化学组成,特别是C/N比值和木质素含量是影响其氮素有效性(对当季作物)的关键因素。各种绿肥中能被当季作物吸收利用的氮素一般仅占其总氮量的25.3±5.0%,其余 Green manure crops, especially leguminous green manure, are not only an important source of soil organic matter but also a good source of crop nitrogen. The latter role of green manure, has always been people’s attention. Many researchers have studied the effectiveness of nitrogen in green manures on seasonal crops and the factors that affect nitrogen availability. It is known that the chemical composition of green manure crops, especially the C / N ratio and the lignin content, are key factors that affect their nitrogen availability (for seasonal crops), in addition to soil properties and crop species. All kinds of green manure can be absorbed by seasonal crops of nitrogen generally accounts for only 25.3 ± 5.0% of its total nitrogen, the rest