初始含水率及容重对农业壤土入渗特性的影响研究

Effect of initial water content and bulk density on infiltration characteristics of loam

为了解初始含水率及容重对农业壤土入渗特性的影响作用,采用室内土柱模拟入渗试验,分别设置了3种初始含水率T1(3.9%,1.375g/cm^3)、T2(8.5%,1.375g/cm^3)、T3(19.3%,1.375g/cm^3)和3种土壤容重T4(19.3%,1.296g/cm^3)、T5(19.3%,1.296g/cm^3)、T6(19.3%,1.436g/cm^3)进行试验。结果表明:(1)初始含水率越小,壤土的入渗速率及累积入渗量越大,入渗速率(I)随时间(t)呈幂函数变化。3种含水率处理下的稳定入渗速率、累积入渗量均表现为T1>T2>T3。(2)容重大小与壤土入渗密切相关,容重越小,土壤颗粒间隙越大,土壤导水能力越强。3种容重处理下初始入渗速率、稳定入渗速率及累积入渗量表现为T4>T5>T6。(3)通过Kostiakov模型、Philip模型和Horton模型对试验结果进行拟合分析,Horton模型的拟合结果优于其他两种模型。

In order to understand the effect of initial water content and bulk density on the infiltration characteristics of loam soil,three kinds of initial water content T1(3.9%,1.375 g/cm^3),T2(8.5%,1.375 g/cm^3),T3(19.3%,1.375 g/cm^3)and three kinds of soil bulk density T4(19.3%,1.296 g/cm^3),T5(19.3%,1.296 g/cm^3),T6(19.3%,1.436 g/cm^3)were set up in this paper.A comparative analysis of the tests was carried out.The results show that:(1)the smaller the initial water content,the larger the infiltration rate and cumulative infiltration rate of loam,and the change of infiltration rate(I)with time(t)is power function.The steady infiltration rate and cumulative infiltration under three water content treatments were T1>T2>T3.(2)The bulk density is closely related to the infiltration of loam.The smaller the bulk density is,the larger the soil particle gap is,and the stronger the soil water conductivity is.Initial infiltration rate,stable infiltration rate and cumulative infiltration amount were T4>T5>T6 under three bulk densities treatments.(3)The Kostiakov model,Philip model and Horton model are used to fit the test results.The fitting results of Horton model are better than those of the other two models.The research results have important theoretical and practical significance for formulating irrigation system of loam farmland and strengthening soil water management.