【摘要】 土壤压实现象普遍存在于农业生态系统中。土壤的压实效应不但会给农业生产带来不良的影响,还可能增加地表径流的产生,从而加快地表水的污染。为了更好地研究压实土壤中的水分、溶质运移以及压实效应对农业生产及生态与环境的影响,该文在原有土壤压实模型的基础上提出了一种两参数改进模型,并以4种原状土壤为例,用离心机法对改进模型进行验证。研究结果表明:改进模型能够较好地模拟土壤的压实过程,且拟合效果好于L模型;虽然改进模型的物理意义和模型精度与Assouline的三参数模型相当,但是参数少、形式简单是改进模型的优势。同时,改进模型的提出对研究土壤水分特征曲线测定过程中的容重变化特性具有重要的参考价值。更多还原

【Abstract】 Soil compaction occurs in agricultural ecosystems commonly. The effect of soil compaction not only has negative effect for agriculture but also could increase the potential pollution of surface water.In order to clarify the movement of soil water and solution in compacted soil and the impact of compaction on agricultural production and eco-environment,an improved model with two parameters was proposed,which relies on an existed soil compaction model.Four undisturbed soils were used in centrifugal procedural to test the improved model.Results show that the improved model fits the data better,and the performances of improved model are better than that of the L model.Although there is no remarkable difference in the theories and performances between improved model and Assouline model,fewer parameters and simple representation are the advantages of the improved model.Meanwhile,the improved model will provide important reference to the study on bulk density changes during soil water characteristic measurement.更多还原