不同耕作措施对南方壤粘土的侵蚀产流产沙影响

Effects of Different Tillage Measures on Runoff and Sediment Yield of Clay in South China

通过微径流场模拟降雨试验,研究了我国南方暴雨条件下不同旱地耕作措施的坡耕地产流产沙情况,并设置了秸秆覆盖、横坡起垄、免耕和纵坡起垄4种南方最为常见的旱地表土耕作方式。在320mm/h的稳定降雨强度下,观测到华南保护性耕作研究区域壤质粘土的产流量与降雨时间符合线次或二次函数关系。由各处理的径流含沙量可知:秸秆覆盖是最有效的防治土壤侵蚀的方式;免耕其次;横坡垄作在降雨初期有一定程度的防治效果,但暴雨依旧会造成土壤结构的破坏;顺坡起垄的水土流失程度最大。分析土壤质地可知:流失的土壤大多为粒径小的粉粒和黏粒,暴雨不仅造成水土流失,也造成表层土壤质地的改变。该研究可为华南地区受暴雨侵蚀的坡耕地提供耕作模式价值相关参考。

To study the slope cultivated field run-off situation during rainstorm,designed a micro run-off rain experiments with different treatments,as for the four common treatments： covered straw,horizontal ridge,vertical ridge and no tillage. It showed that the run-off mount and time obey three or quadratic functions with the south china conservation tillage area soil under the rainfall intensity by 320 mm/h. To have a conclusion,the covered straw was the most effective.way to prevent and controlling soil erosion,followed by no tillage,the horizontal ridge has a certain degree of controlling effect in the early stage of rainfall,but the rainstorm still cause the destruction of soil structure; the vertical ridge loss the most amount of soil. Analysis the soil texture showed that： the loss of soil were small particles and particles mostly,rainstorm not only caused soil erosion,but also the influenced surface soil texture changes. The study can provide a reference value for the cultivated land affected by heavy rain in South China.