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利用风洞模拟试验研究了不同耕作措施的防风效益。研究表明,保护性耕作可明显增加地表粗糙度,提高土壤颗粒起动风速。免耕(NT)措施下地表垫面粗糙度最大,其次为翻耕覆膜(PT),常规耕作(CT)最小。相应地,NT和PT措施下起动风速分别比CT增加31.89%和16.70%。保护性耕作还可减少农田土壤风蚀速率,CT措施下平均风蚀速率是NT和PT措施的3～4倍。由此可知,覆盖措施(覆膜和冬小麦)对减少农田土壤风蚀的作用更突出。
Wind tunnel simulation tests were conducted to study the windbreaking benefits of different tillage practices. Studies have shown that conservation tillage can significantly increase the surface roughness and improve soil particle start-up wind speed. Under no-tillage (NT), surface roughness was the largest, followed by plowing (PT) with the smallest conventional tillage (CT). Correspondingly, the starting wind speeds under NT and PT measures increased by 31.89% and 16.70% respectively over CT. Conservation tillage can also reduce the wind erosion rate of farmland soil. The average wind erosion rate under CT is 3 ~ 4 times of NT and PT measures. From this we can see that the covering measures (mulching and winter wheat) are more prominent in reducing wind erosion of farmland soil.