降雨条件下耕作方式对地表糙度的溅蚀效应

地表糙度是影响坡耕地土壤侵蚀的主要因素之一，为了进一步明确耕作方式对地表糙度的侵蚀效应，该文通过室内人工模拟降雨的方法，就单雨强与组合雨强条件下耕作方式对溅蚀的作用以及地表糙度的变化进行了研究。结果表明，从对照坡面，经耙耱地、人工锄耕、人工掏挖到等高耕作方式的坡面，在雨强0.62 mm/min条件下，不同耕作方式坡面向上坡溅蚀量呈先增加再减小的变化，向下坡和总溅蚀量均呈先增加再减小最后增加的变化；除耙耱地外，其他耕作方式坡面的地表糙度呈减小的变化。在雨强1.53 mm/min条件下，不同耕作方式坡面向上坡、向下坡和总溅蚀量均呈先增加再减小最后增加的变化；地表糙度与对照坡面相反，均呈增加的变化。组合雨强条件下，随降雨强度的增加，耙耱地总溅蚀量与地表糙度呈一直增加的变化趋势；其他耕作方式下，随降雨强度的增加，坡面总溅蚀量呈先增加后减小的变化趋势，地表糙度却呈先减小后增大的变化。这为揭示地表糙度的侵蚀特征提供了一定的理论依据，同时也可服务于黄土高原坡耕地的水土流失治理。

Splash erosion effects of tillage practices on soil surface roughness under different rainfall conditions

Soil surface roughness is one of the main factors which affect soi1 erosion in slope farmland. To further determine the splash erosion effects of tillage practices on soil surface roughness, the effects of tillage practices on splash erosion and changes of soil surface roughness were obtained under the conditions of the single and combined rainfall intensity based on the artificial rainfall simulation experiments. The results showed that the slope erosion effects of tillage practices on soil surface roughness were different from contrast slope, raking cropland, artificial hoe, artificial dig to contour slope. Under the condition of rainfall intensity of 0.62 mm/min, splash erosion of upward slope increased firstly, and then decreased, while increased firstly, and then decreased, and increased finally for splash erosion of downward slope and total splash erosion with the change of tillage practices. Soil surface roughness declined for other tillage practices except for raking cropland. Under the rainfall intensity of 1.53 mm/min, splash erosion of each aspect of slopes increased firstly, and then decreased, and increased finally with the change of tillage practices, while soil surface roughness increased, opposite to the changes of contrast slope. Under the combined rainfall intensity, total splash erosion and soil surface roughness of raking cropland were consistent with the changes of contrast slope with the increasing of rainfall intensity. While total splash erosion of slope increased firstly and then decreased for other tillage practices, reverse to the changes of soil surface roughness. The results provide theory basis for revealing the erosion characteristics of soil surface roughness, and at the same time, it can serve for governing soil and water loss of the slope farmland in Loess Plateau.