氮肥施用对冬小麦氮肥利用率及土壤剖面硝态氮含量动态分布的影响

Effects of Nitrogen Fertilizer in Winter wheat on Its Utilization Rate and Dynamic Distribution of NO - 3N in Soil Layers

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。

Based on the field experiments of six levels of nitrogen fertilizer in winter wheat, the effects of N fertilizer on its utilization rate and dynamic distribution of soil NO - 3N were studied. The results indicates that nitrogen fertilizer utilization rate reduced with the amount of N fertilizer applying, but on the contrast ,the content of soil NO - 3N increased with amount of N fertilizer applied, and under the same level of nitrogen fertilizer,the content of soil NO - 3N increase from topsoil to deep layer of soil (100cm) During the growth of winter wheat, the substancial amount of NO - 3N accumulated in soil layer of 80cm to 100cm, showing a large potential to be leached into ground water and environment.