大豆从分枝开始进入营养生长与生殖生长并进阶段,这个时期经历的时间相当长,因而需要大量氮素营养。虽然大豆根瘤菌有固氮能力,但尚不能满足大豆高产对氮素的需要。在大豆生育期间,特别在分枝后到初花期,适时适量地供应速 Soybeans from the branches into vegetative and reproductive growth and advanced stage, this period of time experienced quite a long time, which requires a lot of nitrogen nutrition. Although soybean rhizobia has nitrogen fixation ability, it still can not meet the needs of high nitrogen yield for nitrogen. During soybean growth, especially in the early flowering after the branches, timely supply of appropriate speed