采用室内模拟、盆栽、微区和田间试验相结合的方法，系统研究了土壤水分在提高氮肥肥效中的作用机制。结果表明：①在一定土壤水分含量范围内，随土壤含水量增加ＮＨ＋４—Ｎ硝化速率增加；②在根系不干扰土体养分的情况下，较高的土壤含水量可加快肥料氮向根系迁移；③良好的土壤水分有利于植物吸收氮素；④水分能促使氮素向籽粒转移，改善籽粒对茎叶的比值，从而增加了玉米的经济学产量，最终反映为土壤水分增高可提高氮肥的增产效果。 The effects of soil moisture on improving the efficiency of nitrogen fertilizer were systematically studied by means of indoor simulation, potted plants, micro-region and field experiments. The results showed that: (1) the NH + 4-N nitrification rate increased with the increase of soil water content within a certain soil moisture content; (2) higher soil moisture could accelerate the migration of fertilizer nitrogen to the root system without disturbing soil nutrients; ③ good soil moisture is conducive to plant nitrogen uptake; ④ moisture can promote the transfer of nitrogen to the grain, improve the ratio of grain to stems and leaves, thereby increasing the economic yield of corn, and ultimately reflected in increased soil moisture can increase nitrogen fertilizer production effect.