带田残茬带宽度及高度对土壤风蚀模数影响的风洞试验

为了探究带宽和残茬高度对土壤风蚀模数的影响，利用野外移动式风洞对阴山北麓地区带田土壤风蚀模数进行了原位测试。结果表明：作物残茬带对间作翻耕地具有保护作用，土壤风蚀模数在全部留茬时最小，全部裸露时最大，残茬与耕翻裸露地间作时居中。不同残茬降低风蚀模数程度不同，莜麦茬可以降低48.92%～67.39%，油菜茬可以降低5.22%～34.36%。不同带宽和残茬高度的间作组合，土壤风蚀模数都随风速的增加而增大，呈指数曲线变化规律。在一定风速吹蚀下，残茬带宽从0.5～3.0?m变化，土壤风蚀模数随带宽的增加而减小，符合幂函数曲线变化规律；残茬高度从5～25?cm变化，土壤风蚀模数随残茬高度增加而线性降低。研究说明减少耕翻和作物留茬是控制风蚀的有效措施。

Wind tunnel test on effect of strip width and crop stubble height on wind erosion modulus

In order to investigate effects of strip width and stubble height on soil wind erosion modulus, in-situ test was conducted at soil wind erosion modulus by a movable wind tunnel in the strip intercropping farmland located at the north foot of Yinshan Mountain. The results showed that crop stubble could protect the intercropping farmland. The erosion modulus reached the minimum in the block keeping whole stubble, the maximum in the whole bare block and the medium in the intercropping strips keeping stubble and autumn ploughed. Effects of different crop stubble on wind erosion modulus were different. Comparing with the whole bare block, the wind erosion modulus decreased by 48.92%-67.39% and 5.22%-34.36% in the autumn-plough strip protected by oat stubble strip and rape stubble respectively. The wind erosion modulus exponentially increased with wind speed. Under the same wind speed, soil wind erosion modulus decreased with the width of strips keeping stubble increased from 0.5m to 3.0 m by power function and decreased linearly with the stubble height increased from 5 cm to 25 cm. The results showed that less tillage and keeping stubble are effective measures to reduce wind erosion.