河西绿洲灌区保护性耕作防风蚀效应的风洞试验研究

Wind Tunnel Tests on Wind Erosion Control Effect of Conservation Tillage in the Hexi Corridor Oasis Irrigation Area

通过对河西地区民勤县绿洲春小麦生产田实施保护性耕作,采用风洞试验,以传统耕作为对照,从风蚀量、风速廓线、风蚀速率和地表粗糙度等方面比较分析了不同保护性耕作措施(免耕不覆盖、免耕秸秆覆盖、残茬压倒处理)的防风蚀效应。结果表明:与传统耕作相比,保护性耕作土壤风蚀量减少,地表风速减小,土壤风蚀速率降低,地表粗糙度增大,土壤风蚀速率与地表粗糙度呈负相关关系。不同保护性耕作措施抑制风蚀的程度不同,4种耕作方式的风蚀速率从大到小依次为传统耕作、残茬压倒、免耕不覆盖、免耕秸秆覆盖,其中免耕秸秆覆盖处理的防风蚀效应最佳。

The paper analyzed the effect of wind erosion control by different conservation tillage measures including no-tillage without covering,notillage with stubble mulching and stubble crushing through the conservation tillage of spring wheat fields of Hexi Corridor oasis irrigation area,by using wind tunnel tests,taking conventional tillage as contrast and comparing with the aspects of wind-blown mass,wind velocity profile,soil erosion rate and roughness of land surface. The outcomes show that comparing with the conventional tillage,the soil wind-blown mass of conservation tillage is decreased,the surface wind speed decreased,the soil erosion rate decreased and the roughness of land surface increased. The soil erosion rate shows negative relationship with roughness of land surface. The different conservation tillage measures have different degrees of wind erosion control. The order of wind erosion intensity from large to small is conventional tillage,stubble crushing,notillage without covering and no-tillage with stubble mulching. Of which,the effect of no-tillage with stubble mulching measure is the best.