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颗粒结构组成是反映土壤质地的重要特征,决定着土壤的水力参数,进而对热量、水分和化学物质迁移过程起主导作用。为揭示土壤颗粒组成对水分运动参数的作用效应,通过灌溉前后不同时空野外试验采样、实验室分析,应用相关分析与通径分析相结合的方法,研究了不同深度(0.1~6m)的砂粒、粉粒、粘粒含量对土壤水分运动参数影响。结果表明:粘粒含量是影响土壤残余含水率(θr)最重要的正作用因子,其次是砂粒含量的负作用;粉粒含量是影响土壤饱和含水率(θs)最大的正作用因子,并对砂粒传递间接的负作用,其次是砂粒含量的负作用,粘粒含量对其没有影响;影响土壤水分特征曲线形状参数α最大的正作用因子是粉粒含量,其次是砂粒含量的负作用和粘粒含量的正作用;影响土壤水分特征曲线形状参数n最大的正作用因子来至于砂粒和粉粒含量,而粘粒含量的正作用也不能忽视;对土壤饱和导水率(ks)影响最大的是砂粒含量的正作用,其次是粉粒含量的正作用和粘粒含量的负作用,同时粘粒含量通过砂粒传递的负作用对其产生影响。砂粒和粘粒对土壤水分特征曲线形状参数n的影响显著,砂粒对土壤饱和导水率直接影响较大,而粉粒和粘粒分别对土壤饱和含水率、残余含水率影响明显。表明通径分析能够透过简单相关的表面深入研究自变量与因变量之间的因果关系,揭示各个因素之间的相对重要性和传递影响。
Particle structure composition reflects the soil texture of the important features that determine the soil hydraulic parameters, and thus on the heat, moisture and chemical migration process play a leading role. In order to reveal the effects of soil particle composition on water movement parameters, the sand samples with different depths (0.1 ~ 6m) were studied by sampling in different fields in different time and space before and after irrigation and laboratory analysis, and applying correlation analysis and path analysis. Influence of silt and clay content on soil moisture movement parameters. The results show that the clay content is the most important positive factor affecting soil residual moisture content (θr), followed by the negative effect of sand content. The grain content is the positive factor that affects the maximum soil moisture content (θs) The indirect negative effect of sand transfer is followed by the negative effect of sand content and the clay content has no effect on it. The positive factor affecting the maximum shape parameter α of soil water characteristic curve is the content of silt, followed by the negative effect of sand content and viscosity The positive effect of grain content; the positive effect factor that affects the maximum shape parameter n of soil water characteristic curve is related to the content of grit and silt, and the positive effect of clay content can not be neglected; it has the greatest influence on the saturated hydraulic conductivity ks Is a positive effect of sand content, followed by a positive role of the grain content and a negative effect of the clay content, while the clay content affects it through the negative effect of sand grain transfer. The effect of grit and clay on shape parameter n of soil water characteristic curve is significant. Grit has a direct impact on soil saturated hydraulic conductivity, while silt and clay have significant effects on soil saturated moisture content and residual water content, respectively. It shows that path analysis can deeply study the causal relationship between independent variables and dependent variables through the simple and relevant surface and reveal the relative importance and the influence of each factor.