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大田试验研究了限水灌溉 (于拔节、开花期各灌 750 m3 .hm-2 )条件下冬小麦对氮素的吸收利用。结果表明 :在 N0～ 375kg.hm-2范围内 ,随氮肥用量加大 ,小麦产量提高 ,每平方百米施 2 2 5kg纯氮的处理达到最高产量 (6 4 6 6 .5kg.hm-2 ) ,在此基础上增施氮肥产量不再增加 ;氮素生理效率随氮肥量的递增而降低 ;限水灌溉下冬小麦对氮素的吸收集中在开花期以前 ,并且增加氮肥量降低了开花—成熟期的氮素吸收量 ;随着施氮量的增加 ,分配于营养器官的氮素比例增加 ,其中以叶片占的比例最大 ,而收获指数则随施氮量增加而降低
Field experiments were conducted to study nitrogen uptake and utilization of winter wheat under water-limited irrigation (750 m3 .hm-2 irrigation at jointing and flowering stages). The results showed that in the range of N0 ~ 375kg.hm-2, the yield of wheat increased with the increase of nitrogen fertilizer, and the highest yield was reached at 225kg per square hectare (666.5kg.hm-2 ), On the basis of which, the increase of nitrogen fertilizer no longer increased; the physiological efficiency of nitrogen decreased with the increment of nitrogen fertilizer; the absorption of nitrogen by winter wheat under limited water irrigation was concentrated before flowering, and the increase of nitrogen fertilizer reduced the flowering- At the mature stage, the nitrogen uptake increased. With the increase of nitrogen application, the proportion of nitrogen distributed to vegetative organs increased, of which leaves accounted for the largest proportion and the harvest index decreased with the increase of nitrogen application rate