To evaluate the effects of ryegrass (Lolium perenne) canopy and roots on eroded sediment particle distribution characteristics, simulated rainfall tests were implemented on grass caopy, roots, and bare slopes. The grass coverage density were 0, 20, 40, and 60%. The results showed that ryegrass canopies mainly contributed to runoff reduction and ryegrass roots primarily contributed to erosion reduction. With increasing rainfall duration, smaller particles (clay and fine silt particles) increased and larger particles (coarse silt and sand particles) decreased in the eroded sediment on the grass slope while the opposite trend was observed for the roots and bare slopes. Moreover, the clay and sand particles were eroded as aggregates and most silt particles were transported in the form of primary particles. Compared to the original soil, larger particles in the eroded sediment mainly occurred on the grass slopes because smaller particles were intercepted by the grass canopies, while smaller particles primarily occurred in the eroded sediment of the root slopes because grass roots inhibited soil erosion. These results illustrate that grass cover can prevent the loss of small particles in the topsoil and avoid soil coarsening, which provides guidance for the comprehensive control of soil erosion.

中文翻译：

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在张家口陡峭的黄土-肉桂斜坡上，黑麦草冠层和根系对暴雨过程中侵蚀性沉积物颗粒分布特征的影响

评估黑麦草（黑麦草）的影响）根据冠层和根系侵蚀的沉积物颗粒分布特征，对草冠层，根和裸露坡面进行了模拟降雨测试。草覆盖密度分别为0％，20％，40％和60％。结果表明，黑麦草冠层主要是减少径流，黑麦草根类主要是减少侵蚀。随着降雨持续时间的增加，草坡侵蚀的沉积物中较小的颗粒（粘土和细粉尘颗粒）增加，较大的颗粒（粗粉尘和沙子颗粒）减少，而在根部和裸露的斜坡上观察到相反的趋势。此外，粘土和沙粒被侵蚀成聚集体，大多数淤泥颗粒以一次颗粒的形式被运输。与原始土壤相比 被侵蚀的沉积物中较大的颗粒主要发生在草坡上，因为较小的颗粒被草冠层截获；而较小的颗粒主要分布在根坡的被侵蚀的沉积物中，因为草根抑制了土壤侵蚀。这些结果说明草皮可以防止表层土壤中的小颗粒流失，避免土壤变粗，为土壤侵蚀的综合防治提供指导。