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分别通过 6个氮水平试验 ,研究了不同氮肥用量对冬小麦氮肥利用率和土壤剖面硝态氮 (NO-3N)动态分布的影响。结果表明 ,氮肥利用率有随施氮量的增加而递减的趋势 ;土壤剖面 NO-3 N含量则具有随氮肥施用量的增加而增加的趋势 ,而在同一氮水平下 ,从土壤表层到深层 (10 0 cm) ,则有递减的趋势。在冬小麦生育期中 ,尤以开花期 80 cm— 10 0 cm土壤剖面累积的 NO-3 N量最多 ,因此最有可能淋洗出根层 ,对地下水造成污染。
Six nitrogen level experiments were conducted to study the effects of different nitrogen rates on the N use efficiency and nitrate nitrogen (NO-3N) distribution in winter wheat. The results showed that the nitrogen use efficiency decreased with the increase of nitrogen application rate. The content of NO-3 N in soil profile tended to increase with the application of nitrogen fertilizer. Under the same nitrogen level, (10 0 cm), there is a decreasing trend. During the growing period of winter wheat, the accumulation of NO-3 N in the soil profile at the flowering stage of 80 cm to 100 cm is most likely, so it is most likely to leach out the root layer and pollute the groundwater.