Biological nitrogen fixation and nitrogen transfer wasdetected by 15N dilution technology. The percentage of BNF, fertilizer nitrogen andsoil nitrogen to nitrogen yield of grass and legume in monoculture and mixture wereanalyzed, respectively.

• 利用同位素15N稀释法测量豆科牧草固氮和转氮能力,分析生物固氮、肥料氮和土壤氮在单、混播条件下羊草和豆科牧草体内的比例,并计算生物固氮量对草地氮产量的贡献率。