农田耕作方式与土壤风蚀强度关系的风洞模拟实验

以土壤风蚀严重的河北坝上康保县为研究区,采用风洞试验的技术手段,对农田耕作方式与土壤风蚀强度的关系进行研究。结果表明,农田留茬与翻耕、农田垄向及农作物残茬高度的差异对土壤风蚀强度有较大影响。垄向平行主风向的风蚀强度大于垄向垂直主风向的风蚀强度。风速越大,垄向不同造成的风蚀强度的差异越大,尤其是当风速≥15m/s时,风蚀强度的差异表现得较为明显;风蚀强度与留茬高度呈负相关;翻耕地的风蚀强度大于任何留茬地的风蚀强度;风蚀强度与风速变化呈现出指数函数变化规律。因此,农田垄向垂直主风向、作物收获后不进行翻耕、留有适度茬高、优先种植残茬硬度较大的莜麦作物,这样的耕作方式可有效降低土壤风蚀强度,缓解河北坝上地区农田土壤风蚀状况。

Experiment on relationship between different cultivation patterns and soil wind erosion intensity by wind tunnel

The Kangbao County of Bashang in Hebei Province where wind erosion on land was serious was taken as research area to study the different cultivation patterns of farmland as well as its impact on wind erosion of land by the technical means of wind tunnel test explanation.The results show that keeping stubble or plowing,field ridges and different stubble height had influence on soil erosion.Compared with that the ridge of the farmland is vertical to the main wind direction,wind erosion intensity of the farmland which ridge is parallel to the main wind direction is relatively intense.When the wind speed was big,the difference of wind erosion intensity caused by different ridge was big.When the wind speed is more than 15m / s,the effect of field ridges on soil erosion intensity was far more dramatic.Wind erosion intensity and stubble height was negatively correlated.Compared with stubble field,wind erosion intensity of the plow tillage field was big.Wind erosion intensity and wind speed showed the variation of the exponential function.Different cultivation patterns of the field such as ridge is vertical to the main wind direction,keeping suitable stubble height,do not flow after harvest and give priority to plant naked oats which having big stubble hardness can be effective measures to reduce wind erosion intensity and bring soil wind erosion remission in Bashang Area of Hebei Province.