蔗叶还田对红壤薄土坡耕地坡面侵蚀过程阻控机制研究

Study on the resistance and control mechanism of sugarcane leaf returning to field on slope erosion process of red soil thin sloping farmland

基于广西红壤区保护性耕作的实际,在不同甘蔗叶覆盖方式下,对不同蔗叶长度和蔗叶量条件下坡耕地侵蚀过程与特征进行分析,研究不同蔗叶覆盖特征对坡耕地减流减沙效益的影响。结果表明:不同的蔗叶覆盖方式、蔗叶长度和蔗叶覆盖量对坡面减流减沙效益的影响都达到了极显著的水平(P<0.05),对减流减沙效益贡献最大的因素是蔗叶覆盖量。蔗叶表土覆盖条件下减流效果较好,蔗叶混合覆盖条件下减沙效果较好。蔗叶表土覆盖条件下减流减沙比(R_(rs))大小随着蔗叶覆盖量的增加呈现先减小后增加的趋势,蔗叶表土覆盖条件下的减沙水代价明显大于蔗叶混合覆盖。

Based on the practice of conservation tillage in red soil areas of Guangxi,the authors analyze the erosion process and characteristics of sloping farmland under different sugarcane leaf covering modes,different sugarcane leaf lengths and amounts,and study the impact of different sugarcane leaf covering characteristics on the runoff and sediment reduction benefits of sloping farmland.The results indicate that different sugarcane leaf covering modes,leaf lengths and covering amounts have a significant impact on the runoff and sediment reduction benefits of slopes(P<0.05),and the most significant factor contributing to the runoff and sediment reduction benefits is the covering amount of sugarcane leaf.The runoff reduction effect is better under the condition of sugarcane leaf topsoil cover,and the sediment reduction effect is better under the condition of sugarcane leaf mixed cover.The reduction ratio of runoff and sediment(Rrs)under the condition of sugarcane leaf topsoil cover shows a trend of decreasing first and then increasing with the increase of sugarcane leaf covering amount.The cost for water and sediment reduction under the condition of sugarcane leaf topsoil cover is significantly greater than that under sugarcane leaf mixed cover.