【摘要】 论述了三个问题。①大豆根系生长的三个特点是大豆肥田的机制。②大豆收获后土壤氮素的盈亏是环境条件的差异引起的。③大豆肥田机制与多年生豆科牧草的肥田机制是相似的更多还原

【Abstract】 Three problems are discussed in this article.①The 3 particular properties of soybean roots growth are the mechanism of soybean for fertilizing soil.②The profit or loss of total nitrogen in soil after soybean harvest is leaded by different environment condition.③The mechanism for fertilizing soil of soybean and perenial legumes in similar. There are also initial comment on the proverbs of soybean stubble field更多还原