Characteristics of nitrogen accumulation,distribution and translocation in winter wheat on dryland

A field experiment was carried out to study the uptake,accumulation and translocation of nitrogen of four winter wheat varieties at different N-levels on the dryland.This experiment was designed using a split-plot design.5 levels of nitrogen fertilizers were the main plots and 4 varieties were the subplots.The application rate of nitrogen fertilizer was 0,60,120,180 and 300 kg/ha,respectively;and the varieties was Shaan 253(V1),Shaan 229(V2),Xiaoyan 503(V3) and Xiaoyan 22(V4).The results showed that the highest N uptake in the growth period occurred from reviving stage to anthesis stage.The nitrogen accumulation rate,which had significant differences between different varieties,increased as N rate increased.When the rate of N fertilizer was higher than 180 kg/ha,grain yield was decreased with the increase of N rate,indicating plant receiving the luxury N uptake.The nitrogen accumulation of Xiaoyan 22 variety was the highest,followed with Shaan 253,Xiaoyan 503 and Shaan 229.The proportion of N accumulated in leaf and stem was high before the anthesis stage;and the accumulated N rate in stem reached peak at the anthesis stage.The residual N in leaf and stem at the maturing stage showed an obvious upward trend with the increasing N rate.The highest N accumulation of wheat grain took place at the N rate of 180 kg/ha.The N transportation efficiency of different organs during grain filling stage ranked in the following order,leafspikestem.Different varieties had various N use efficiency.Compared to other varieties,Xiaoyan 22 had higher N recovery,N agronomic efficiency and N physiological efficiency.This showed that Xiaoyan 22 had a high efficiency of N uptake,translocation and utilization.