湿润速度对土壤表面强度和土壤团聚体结构的影响

为揭示地表结皮形成的物理机制和防止结皮形成的措施提供理论支持，该文以中国3种典型的土壤（黄土、红壤和黑土）为研究对象，采用2 mm/h（慢速），10 mm/h（中速），50 mm/h（快速）3种湿润速度，研究无降雨条件下不同湿润速度对土壤表面强度和土壤团聚体结构的影响。结果表明：不同湿润速度对3种土壤的表面强度的影响程度由大到小为黄土，黑土，红壤；3种土壤中，红壤的团聚体稳定性最好，其次是黑土，黄土最差；除黄土和红壤各自慢速湿润与中速湿润对平均质量直径（MWD）的影响差异不显著，其余各种土壤不同湿润速度对MWD的影响差异均显著。

Effects of wetting rate on soil surface strength and aggregate stability

To illuminate the physical mechanism for the formation of soil surface crust and present the theoretical foundation for preventing the formation of crust, three types of arable soils in China, for example, loess, red and black soils, were used to investigate the effects of wetting rate on surface strength and aggregate stability without rainfall, under wetting rates of 2 (slow), 10 (middle) and 50 mm/h (fast). The results indicate that the effects of wetting rates on surface strength are decreased in the order of loess> black soil> red soil. The aggregate stabilities have the order of red soil> black soil> loess. Except slow and middle wetting rate for loess and red soil, there are significant differences of mean weight diameter (MWD) among different wetting rates with different soils.