旱作农田近地表风沙运动与防风蚀效果

Drought Farmland Near Surface Blown Sand and Wind Erosion Controlling Effect

针对农田沙害,用移动式风蚀风洞及相关配套设备对莜麦留茬、砾石覆盖和传统旱作农田地表进行原位测试,研究它们的近地表风沙运动规律,探索莜麦留茬和砾石覆盖对旱作农田土壤风蚀的作用机理和防护效果,从而为农田风蚀防治提供技术依据。研究表明,莜麦留茬、砾石覆盖近地表风沙运动与对照秋翻地明显不同;受莜麦残茬和砾石覆盖的阻挡、疏散作用,风沙活动层提升,近地表风速不同程度削弱;输沙量小于对照秋翻地并且在近地表一定高度处出现极大值。抗风蚀效率分析证明,莜麦留茬和砾石覆盖对旱作农田防治风蚀都有重要的作用,但砾石覆盖不如莜麦留茬的防风蚀效果好。

Aiming at farmland wind erosion sand calamity,in situ testing was adopted to make test for oat stubble,grave covering and traditional drought farmland by using movable wind erosion tunnel and its matching equipment.In order to provide technical basis,blown sand movement law was researched for the three kinds of farmland,and the mechanism and protection effect of soil erosion were explored for the oat stubble and grave covering affecting drought farmland.It is showed that near surface blown sand movement of oat stubble and grave covering are obviously different from autumn-ploughed farmland,the blown sand movement layer was lifted,near surface wind speed was weakened at different degrees,sediment discharge is less than autumn-ploughed farmland＇s and would have maximum value in certain height,because of barrier and evacuation effects of oat stubble and grave covering.By anti-erosion efficiency analyzing,it is showed that oat stubble and grave covering have important effect on drought farmland for wind erosion controlling,and the effect of the latter is less than the former.