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通过室内模拟降雨试验对不同土壤容重的草甸土坡面养分流失特征进行研究。结果表明:土壤容重是坡面草甸土养分流失的重要影响因子,土壤容重不同,降雨引起的坡面表土养分流失的程度不同。硝态氮主要随径流流失,占总流失量的55%～79%,70%～84%的有效磷和速效钾随泥沙流失。不同形态的养分在流失泥沙中有富集现象,但富集比各不相同。土壤容重在0.8～1.2g/cm3之间变化时,随土壤容重增加,土壤孔隙度减小,入渗能力减弱,土壤养分在降雨侵蚀力作用下流失量不断增加。但随容重的继续增大,土壤抗蚀性增大,产沙量减小,养分流失量也有减小的趋势。在降雨、坡度等一定的条件下,土壤最容易被侵蚀而发生养分流失的容重范围为1.2～13g/cm3。
Indoor simulated rainfall experiments were conducted to study the nutrient loss characteristics of meadow soil with different soil bulk density. The results showed that soil bulk density was the important factor of nutrient loss on the meadow soil. The soil bulk density was different. The degree of nutrient loss on topsoil caused by rainfall was different. The main nitrate-nitrogen loss with runoff, accounting for 55% to 79% of total loss, 70% to 84% of available phosphorus and available potassium loss with sediment. Different forms of nutrient enrichment in the sediment loss, but the enrichment than the different. When soil bulk density varied from 0.8 to 1.2 g / cm3, with the increase of soil bulk density, the soil porosity decreased and the infiltration capacity weakened. The loss of soil nutrients under the action of rainfall erosion increased continuously. However, with the weight continues to increase, the soil corrosion resistance increases, sediment yield decreases, nutrient loss has also decreased. Under rainfall and slope conditions, the bulk density range of soil nutrient loss is 1.2 ~ 13g / cm3.