黄土残塬区人工降雨条件下坡耕地水蚀研究——Ⅲ.坡耕地小麦休闲期秸秆覆盖的防蚀效应

Water Erosion on Slope Farmland in Loess Broken Plateau Regionby Simulated Rainfall. Effects of Straw Mulch Controlling Erosion in the Wheat Fallow on Slopeland

采用室内径流冲刷和野外人工降雨模拟试验相接合的方法，对隰县黄土残塬区坡耕地小麦休闲期秸秆覆盖的阻延流速、增加糙率，以及减少土壤侵蚀量的作用和影响作了探讨与研究。结果表明：秸秆覆盖具有阻延流速（可达６～２５ｃｍ／ｓ）和增加糙率（可增加０．０２～０．０３）的功能，能够延缓起流时间，降低洪峰流量和沙峰值，减少泥沙含量和控制土壤侵蚀（可减少５０％～８０％），但其效果随坡度的增加而减弱，随覆盖厚度的增加而增加。

By the basis of experiments of runoff scouring and simulated rainfall, the effects of straw mulch controlling erosion in the wheat fallow on the slopeland in loess broken plateau region of Xixian were studied, the results show that straw mulch can slow down of velocity of flow ( 625 cm/s),enhance rough coefficient (0.020.03), put off runoff beginning, reduce peak value of flow and sediment, and control erosion ( reducing rate 50%80%). Effects of straw mulch controlling erosion decreases as slope gradient increasing and decreases as thickness of straw mulch increasing.