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采用人工模拟降雨实验,研究了近地表土壤水分条件,尤其是土壤水分饱和条件对土壤侵蚀过程中农业非点源污染物运移的影响.结果表明,前期近地表土壤水分条件对土壤侵蚀过程中农业非点源污染物的迁移有着很大影响.饱和含水量时径流及泥沙中非点源污染物的流失浓度和流失量大于非饱和含水量,且前期近地表土壤含水量越大,径流及泥沙中农业非点源污染物的流失浓度和流失量越大.土壤氮素的主要流失途径是降雨所产生的径流,约占总流失量的90.4%～99.8%;土壤磷素的流失途径是降雨径流和侵蚀产沙,分别占总流失量的2.67%～23.5%和76.5%～97.3%.同时,土壤质地对磷素养分的流失有很大影响,杨凌土随泥沙流失的DP浓度和流失量均大于安塞黄绵土.最后,提出了采取最佳管理措施等控制农业非点源污染的针对性建议.
The effects of near-surface soil moisture conditions, especially soil moisture saturation conditions on the transport of agricultural non-point source pollutants during soil erosion were studied using simulated rainfall experiments. The results showed that near-surface soil moisture conditions had an important effect on soil erosion The migration of non-point source pollutants in agriculture has a great impact on the migration of saturated non-point source pollutants.The concentration and loss of non-point source pollutants in runoff and sediment are more than that of unsaturated water when saturated water content, And the greater the loss concentration and loss of agricultural non-point source pollutants in the sediment.The main loss way of soil nitrogen is the runoff generated by rainfall, accounting for 90.4% ~ 99.8% of the total loss; the loss of soil phosphorus The pathways are rainfall runoff and erosion and sediment yield, accounting for 2.67% -23.5% and 76.5% -97.3% of the total loss respectively. Meanwhile, the soil texture has a great impact on the loss of phosphorus nutrients, DP concentration and loss are greater than the Ansai loamy soil.Finally, the paper put forward some suggestions on how to take the best management measures to control agricultural non-point source pollution.