氮磷配合对土壤氮素径流流失的影响

大田试验研究结果表明 :增施N、P均能增加作物的产量和减少水土流失 ;当N、P用量分别达到 5 5 .2kgN/hm2 和 90kgP2 O5/hm2 时 ,泥沙有机质和全氮流失最少 ,流失量分别为 2 0 89和 1 75kg/km2 ;当N、P用量分别为 5 5 .2kgN/hm2 和 4 5kgP2 O5/hm2 时 ,土壤矿质氮流失最小 ,其流失量仅为 2 7.9kg/km2 ;作物对土壤氮素的吸收 ,可减少土壤氮素的流失 .

The field experiment of soil erosion was conducted. With increasing amounts of N and P fertilization, soil erosion and runoff yields are decreased gradually. Losses of soil organic matter and total nitrogen in sediment reached a minimum under the fertilization of 55 2kg N/ha ad 90kg P 2O 5/ha. However, when 55 2kg N/ha and 45kg P 2O 5/ha were used, soil available N loss was decreased to a minimum of 27 9kg/ha. The decrease in soil N loss in erosion was due to crop absorbing of soil N.