土壤一维垂直入渗控制界面的试验研究

Study on Control Interface of One-dimensional Vertical Infiltration of Soil

基于不同土壤结构条件下的大田土壤水分入渗试验,通过分析对比结构良好表层土壤（容重在1.2~1.4 g/cm3之间）与特别疏松的表层土壤（容重在1.0~1.2 g/cm3之间）入渗率过程的特性和差异,揭示了土壤稳定入渗控制界面下移的现象。在对土壤的干容重与稳定入渗率之间的关系进行分析的基础上,确定了不同表层土壤结构条件下的入渗控制界面的位置。研究结果表明,结构良好的土壤的入渗控制界面在表层,特别疏松的土壤的入渗控制界面则在犁底层;入渗控制界面在表层的入渗属于无压入渗,入渗控制界面在犁底层的入渗属于非饱和土壤的有压入渗。

Based on water infiltration of field soil under different structural conditions,the phenomenon was revealed that the control interface of steady infiltration rate of soil was depressed by analyzing and comparing the characteristics and differences of infiltration process between well-structured surface soil with bulk density of 1.2 to 1.4 g/cm3 and particularly loose surface soil with bulk density of 1.0 to 1.2 g/cm3.Positions of infiltration control interface under different conditions of surface soil structures were fixed on the basis of analysis of relations between the bulk density and steady infiltration rate of soil.The results indicate that the control interface of well-structured soil was at the upper layer,while the control interface of particularly loose soil was at the plow pan,and the infiltration type of the former belonged to non-pressure irrigation while the latter belonged to pressure infiltration of unsaturated soil.