施氮期对夏玉米氮素积累运转及氮肥利用的影响

通过设置不同施氮期试验,研究对夏玉米植株氮素积累运转及氮肥利用率的影响。结果表明,与不施氮相比,施氮提高了植株氮素积累量、子粒氮素积累量和氮素收获指数(NHI)。吐丝后穗部氮素积累迅速增长,茎鞘氮素转运主要集中在灌浆初期,叶片氮素转运主要发生在灌浆中后期。施氮使氮生理效率较不施氮处理平均下降了16%,处理间氮肥效率差异不显著。植株总吸氮量的60%～70%主要集中在吐丝至成熟期,以3叶期施氮+12叶展追氮处理氮吸收最多,氮肥利用率(NUE)最高,与其他处理相比,3叶期施氮+12叶展追氮处理NUE分别提高了21.8个百分点和22.8个百分点。

Effects of Nitrogen Application Period on Nitrogen Accumulation, Translocation and Nitrogen Use Efficiency of Summer Maize

Effects of nitrogen application period on nitrogen accumulation, translocation and nitrogen use efficiency were studied. The main results as following: compared with CK, nitrogen application increased NHI and amounts of nitrogen accumulation in plants and grain. The amounts of nitrogen accumulation in ear increased quickly after silking, nitrogen translocation of stem and sheath happened mostly in early filling stage, nitrogen translocation of leaf happened mostly in middle and later filling stage. Nitrogen application made nitrogen physiological efficiency declined 16%, nitrogen fertilizer efficiency was no obvious difference among three treatments. The 60% - 70% in total nitrogen accumulation amounts of plants was accumulated from silking to maturing stage, the nitrogen accumulation amounts and nitrogen use efficiency of T4 were highest, compared with T2 and T3, the NUE of T4 heightened 21.8 and 22.8 percent points.