大豆种子蛋白质高,和大多数其它豆科植物一样,它有两种不同的氮素同化系统——氮素固定和硝酸盐的还原。人们一直试图估计这两种氮素同化系统对大豆氮素营养和高产潜能的相对作用。根据桥本(1976)的试验结果,是种植后16—54天固氮占该时期同化总氮量的31.4％,55—83天是40％,84—113天是57.9％,114—137天是45.4％。这说明,大豆在营养 Soybean seeds are high in protein, and like most other legumes, they have two distinct nitrogen assimilation systems - nitrogen fixation and nitrate reduction. People have been trying to estimate the relative contribution of these two nitrogen assimilation systems to soybean nitrogen nutrition and high yield potential. According to the results of Hashimoto (1976), nitrogen fixation accounts for 31.4% of the total nitrogen assimilated during the period from 16 to 54 days after planting, 40% from 55 to 83 days, 57.9% from 84 to 113 days, and 114 to 137 days from 45.4%. This shows that soy is in nutrition