六十年代以来,能源危机日益尖锐,世界各国对绿肥效益的研究再度兴起,并提出了一些新见解。一、绿肥对保持养分平衡的效益绿肥作物常作为覆盖作物栽培,一般都在秋季播种,可以起到减少养分淋失、维护平衡的效益。每0.15亩绿肥可使土壤硝态氮的淋失减少27%、p_2o_5减少17%、k_2o减少14.8%。要得到这种效益,最主要的是少耕或免耕,这一措施的确能以最少代价而有效地保护土壤。同时,由于根系生长与耕性改良,还可给土壤带来物理效益。二、绿肥能改善农作物的碳素 Since the 1960s, the energy crisis has become more and more acute. Researches on the benefits of green manure all over the world have arisen again and some new ideas have been put forward. First, the effectiveness of green manure to maintain nutrient balance Green manure crops often cover crop cultivation, are generally sown in the fall, can play to reduce nutrient leaching, to maintain the balance of benefits. Per 0.15 mu of green manure could reduce nitrate leaching by 27%, p_2o_5 by 17% and k_2o by 14.8%. To achieve this benefit, the most important thing is to reduce or no tillage, and indeed this measure can effectively protect the soil at the least cost. At the same time, physical benefits to the soil can also be achieved due to root growth and tillage improvement. Second, green manure can improve the crop carbon