氮肥施用量对冬小麦氮肥利用率及土壤剖面NO_3^--N动态分布的影响

Effects of Application Level on Utilization Ratio of Nitrogen Fertilizer and Dynamic Distribution of Cross section of Soil NO_3^--N for Winter Wheat

通过 6个氮水平小区试验 ,研究了不同氮肥用量对冬小麦氮肥利用率和土壤剖面 NO3 -- N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 NO3 -- N含量则有随氮肥施用量增加而增加的趋势 ,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 ,以开花期 80～ 10 0 cm土壤剖面累积的 NO3 -- N量最多 ,因此最有可能淋洗出根层 。

Based on the field experiments of six levels of nitrogen fertillzer applied to winter wheat,the effects of quantity on its utilization ratio and dynamic distribution of soil NO 3 - N were studied The results indicated that the nitrogen fertilizer utilization ratio reduced with increasiag amount of N fertilizer application.but on the contrast,the content of soil NO 3 - N increased with iucreasing amount of N fertilizer application ,and under the same level of nitrogen fertilizer,from topsoil to deep layer of soil (100 cm),the content of soil NO 3 - N was decreased According to the amount of NO 3 - N in the deep layer soil during the growth of winter wheat,the amount of NO 3 - N accumulated in the surface layzs of soil of 80 cm to 100 cm was the higbest so it was very easy to seep into ground water and pollute the environment.