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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。
By setting different nitrogen application period, the effects of nitrogen accumulation and nitrogen utilization and N recovery of summer maize were studied. The results showed that compared with no nitrogen application, nitrogen application increased plant nitrogen accumulation, nitrogen accumulation and nitrogen harvest index (NHI). After silking, the accumulation of nitrogen increased rapidly, and the nitrogen transport in stems and sheaths mainly concentrated in the early filling stage. The nitrogen transport in leaves mainly occurred in the late filling stage. Nitrogen application decreased the average nitrogen physiological efficiency by 16% compared with no nitrogen treatment, and no significant difference in nitrogen efficiency between treatments. From 60% to 70% of the total nitrogen uptake in the plant was mainly from silking to maturity, nitrogen uptake by topdressing nitrogen at the 3-leaf stage and nitrogen uptake by leaf-topping at the 12th stage showed the highest NUE and highest nitrogen use efficiency (NUE). Compared with other treatments , NUE increased by 21.8% and 22.8% respectively in the three-leaf stage with nitrogen application +12 leaf nitrogen application.