冬小麦对不同时期施用的尿素N的吸收利用

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。

NITROGEN TRANSFORMATION IN SOLL AND ITS UPTAKE BY WINTER WHEAT

The nitrogen transformation in soil and its uptake by winter wheat at the different growth stage were studied by using 15N-urea.The results indicated that NO3--N content in soil increased rapidly when the urea was applid.It was found that about 90% of the NO3--N content was in layer between 0 and 20cm in depth.There were two peaks of N absorption for wheat.One was in the jointing-booting stage and another was in the filling stage.The amount of nitrogen uptake at tne first peak stage showed a positive correlation to the yield of wheat,r=0.7715.The results also indicated that there were correlation between dry weight of wheat,the amount of nitrogen uptake and the nitrogen content in the fertilizer.And,nitrogen in fertilizer and that in soil were absorbed by wheat in proper proportion.