%0 Journal Article
%T Effect of reduced N application on N utilization and balance in winter wheat- summer maize cropping system<br>减量施氮对冬小麦-夏玉米种植体系中氮利用与平衡的影响
%A LIU Xuejun
%A JU Xiaotang
%A ZHANG Fusuo
%A <br>刘学军
%A 巨晓棠
%A 张福锁
%J 应用生态学报
%D 2004
%I 
%X A field trial on a calcareous soil was carried out at an experimental station of China Agricultural University with the objective of assessing the effect of reduced nitrogen application on N utilization and N balance in a winter wheat-summer maize cropping system. Before this study, the trial has been conducted for one rotation cycle of wheat and maize with four-fixed N rates of 0, 120, 240 and 360 N kg.hm-2 per crop. In this study, each plot was divided into two sub-plots for two N application rates: normal N application(original rate) and reduced N application(reduced rate). The results showed that the grain yields of wheat and maize reached the platform at N rate of 120 kg.hm-2(N120), and then almost kept the same level regardless of the further increase of N rate(N240 and N360). The N uptake by wheat and maize followed the similar tendency like their yield. The grain yield and N uptake of wheat were not significantly declined with the half reduction of original N rate except the treatment N120. However, the same items in maize significantly declined with the further reduction of N fertilizer to zero. The residual NO3-N(main source of mineral N) in reduced N sub-plots was significantly lower in 0-1 m soil layer, but not different in 1-2 m soil layer compared with those receiving original N rate, indicating that 1-2 m soil NO3-N could hardly be utilized by crops. N balance calculation further showed that the N recovery by crops could be largely raised by the reduction of N fertilizer, while the apparent N loss rate decreased in wheat-maize rotation, respectively. Thus, the reduction of fertilizer N under high N rate can significantly increase N use efficiency and reduce NO3-N accumulation and apparent N loss.
%K Reduction of N application
%K Wheat-maize cropping system
%K Residual nitrate N
%K N balance<br>减量施N
%K 冬小麦-夏玉米种植体系
%K 硝态氮残留
%K N平衡
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=90BA3D13E7F3BC869AC96FB3DA594E3FE34FBF7B8BC0E591&jid=42FEDDFE54F8BCD9D5FD1926ABDD7722&aid=4AB9E89A40A75D0A&yid=D0E58B75BFD8E51C&vid=23CCDDCD68FFCC2F&iid=38B194292C032A66&sid=D9202C57BAB9096F&eid=8C5DE51F0A009A0F&journal_id=1001-9332&journal_name=应用生态学报&referenced_num=21&reference_num=15