施氮对稻麦轮作区小麦地上器官干物质及氮素累积运转的影响

Effect of Nitrogen Application on Accumulation and Transportation of Matter and Nitrogen in Above-ground Organs of Wheat in Rice-wheat Rotation Area

为给长江中下游稻麦轮作区小麦的高产栽培提供理论依据,以扬麦10号为材料,设置0、93.75、168.75和243.75 kg/ha四个氮肥处理水平(分别用N0、N1、N2和N3表示),研究了施氮对小麦地上器官干物质及氮素累积运转的影响。结果表明,增施氮肥提高了小麦群体叶面积指数,N3处理与N2处理差别不大,增施氮肥不影响叶面积指数的动态变化规律。干物质量随着施氮量的增加而增大,营养器官转运率以不施氮(N0)处理最大,对籽粒的贡献率以N2处理最大。增加施氮量提高了小麦各个生长时期氮素累积量,N3处理在收获时茎秆中有较高的氮素残留,降低了氮肥利用效率。增施氮肥提高了小麦产量,N2处理与N3处理之间差异不显著。氮肥生理效率以N1最高,氮肥利用效率和农学效率均以N2最高。

A field experiment was conducted to study the effect of nitrogen application on accumulation and transportation of nitrogen and dry matter of aboveground organs in wheat and in the lower yangtze region. This experiment used Yangmai 10 as the material, and four nitrogen levels of N1（0 kg/ha）, N2（93.75 kg/ ha）, N3（168.75 kg/ha） and N4（243.75 kg/ha） were set up. The results showed that increasing nitrogen fertilizer could increase leaf area index （LAI） of wheat , but no obvious differences existed between N2 and N3, and increasing nitrogen ferti-lizer did not affect the dynamic change of LAI. With the amount of nitrogen increasing, more dry matter was obtained, and the highest nutrition organ transfer rate was observed in NO, the highest contribution rate to grain were observed in N2. The transfer rate of stem was significantly higher than that of leaf. The increase in the amount of fertilizer increased the accumulated amount of nitrogen in all growing periods of wheat. There were higher residual nitrogen in stem of N3 after harvest, this would reduce nitrogen utilization rate. Increasing nitrogen would increase wheat yield, but no obvious differences existed between N2 and N3. The highest physiological efficiency of nitrogen was observed in N1 and the maximum utilization efficiency of nitrogen fertilizer was in N2.