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长期的风蚀使土壤不断分选,直径少于50～100微米的细颗粒和团聚体被风吹扬,直径100～500微米的土粒和团聚体沿地表滚动,直至落到背风隐蔽处。运动中颗粒磨损、细化,团聚体分裂、粉碎,变成能被风力搬运的细颗粒。 这种分选过程的长期进行,使表层土质地逐渐变粗,腐殖质日益减少。有些资料表明,这些变化进展缓慢,其规模大小需要若干年才能清楚地显现出来,特别是在农田耕作扰动了上部土壤层次的情况下尤其如此。 1948年,在堪萨斯州曼哈顿进行风蚀研究不久,项目主持人W·S·Chepil和联邦土壤保持局的土壤学家Claude Fly在堪萨斯州西部农田上选了10处样地采集土样,后来提出一份说明中部和南部大平原风蚀土物理和化学性质的报告。在这份1984年风
Long-term wind erosion causes the soil to be continuously sorted. Fine particles and agglomerates of less than 50 to 100 microns in diameter are blown by the wind. Soil particles and agglomerates of 100 to 500 microns in diameter roll along the ground until they fall to the shelter of the leeward. Particle movement during wear, refinement, agglomeration split, crushed into fine particles can be handled by the wind. This long-term sorting process, so that the topsoil gradually become thicker, less and less humus. Some sources indicate that these changes have been slow to progress and that their size will take years to be clearly demonstrated, especially if farmland disturbance disturb the upper soil level. Shortly after the wind erosion study was conducted in Manhattan, Kansas, in 1948, project host W. Chepil and federal soilbinder Claude Fly selected 10 sample plots to collect soil samples from farmland in western Kansas, A report describing the physical and chemical properties of wind-eroded soil in the Great Plains of Central and Southern China. In the 1984 wind