豆科作物有根瘤菌共生,它所需要的氮素有很大一部分由根瘤菌固定空气氮素而来。一般认为豆科作物体内含氮量约有三分之一取自土壤,三分之二由根瘤菌固定空气氮素获得。然而,豆科作物不同发育时期固氮量是否相同,氮素在植物体内的分配情况,需要研究。 Legume crops Rhizobium symbiotic, it requires a large part of the nitrogen from the Rhizobium fixed air nitrogen from. It is generally believed that about one-third of the nitrogen content of leguminous crops is taken from the soil and two-thirds are obtained from immobilized air nitrogen by Rhizobium. However, it is necessary to study whether the amount of nitrogen fixation is the same in different developmental stages of leguminous crops and the distribution of nitrogen in plants.