中文摘要：

为探究不同覆盖措施对养分流失及其粒径分布的影响,采用人工模拟降雨试验的方法,模拟了不同雨强（30,60mm/h）和不同覆盖物（枯落物、砾石）下,不同覆盖度对褐土坡面养分流失的影响,并对侵蚀土壤的粒径分布、养分流失浓度进行了分析。研究表明：（1）不同覆盖措施均能有效减少土壤流失,250g/m^2的枯落物和盖度为50%的砾石覆盖可减少91%～98%和68%～91%的土壤流失。（2）褐土坡面下,被侵蚀土壤中有机质、速效氮、速效磷的浓度基本不随覆盖条件的变化而变化,而速效钾的浓度随坡面覆盖度的增加可增至裸地对照组的144%～325%。（3）土壤中养分流失随坡面覆盖度增加而减少,250g/m^2的枯落物和盖度为50%的砾石覆盖可减少64%～96%和43.29%～94.39%的养分流失。（4）被侵蚀土壤的粒径显著小于侵蚀前土壤,并且侵蚀模数越大,被侵蚀土壤的粒径组成越接近于原状土。

英文摘要：

To study the effects of different mulching methods on soil nutrient loss and soil particle size distribution,we simulated different rainfall intensities（30mm/h,and 60mm/h）and different mulching methods（litter,gravel）by an artificially simulated rainfall experimental system.The results showed that：（1）Both litter cover and gravel cover could reduce soil erosion effectively.A 250g/m^2 litter cover and a 50% gravel cover could reduce soil erosion by 91%-98%and 68%-91%,respectively.（2）The concentration of organic matter,available nitrogen,and available phosphorus did not change with the variation of coverage,but the concentration of available potassium was increased to 144%-325% of that of the control group.（3）The total nutrient loss decreased with the increase of coverage.A 250g/m^2 litter cover and a 50% gravel cover could reduce the nutrient loss by 64%-96%and 43%-94%,respectively.（4）The particle size of the eroded soil was significantly smaller than that of the soil before erosion,and the larger the erosion modulus,the closer the soil particle size was to the undisturbed soil.