大豆和大多数豆科植物一样,有两种不同的氮素同化系统——氮索固定和硝酸盐的还原。人们一直试图估计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,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、要想获得高产量,两种氮素 Soybeans Like most legumes, there are two different nitrogen assimilation systems - nitrogen fixation and nitrate reduction. People have been trying to estimate the relative contribution of the two nitrogen assimilation systems to soybean nitrogen nutrition and high yield potential. According to the results of Hashimoto (1976), nitrogen fixation accounted for 31.4% of the total nitrogen assimilated during this period, 40% for 55-83 days and 57.9% for 84-113 days after planting 16-54 days after planting. 45.4% for 114-137 days. This shows that in order to obtain high yields, two kinds of nitrogen