本文应用~(15)N尿素研究了不同施肥时期下尿素N在土壤中的转化和小麦对肥料氮的吸收利用。结果表明,尿素施入土壤后,硝态氮含量急剧增加。播前底施尿素有更多的硝态氮累积在20～40cm土层中。小麦对肥料氮的吸收高峰在4月13～18日,即拔节孕穗期,高峰期的吸氮量与小麦产量呈正相关,r=0.7715。 In this paper, ~ (15) N urea was used to study the transformation of urea N under different fertilizations and soil nitrogen uptake by fertilizer. The results showed that the content of nitrate nitrogen increased rapidly when urea was applied to the soil. Sowing urea before the end of more nitrate accumulation in 20 ~ 40cm soil layer. The peak of nitrogen uptake by wheat was between April 13 and April 18, that is, at jointing and booting stages. The nitrogen uptake at the peak was positively correlated with the wheat yield, r = 0.7715.