容重对土壤水分入渗能力影响模拟试验

Simulated experiment on effect of soil bulk density on soil infiltration capacity

通过人工改变土壤颗粒级配,配制典型砂壤、中壤、黏壤,并设置不同容重水平,用土柱积水入渗模拟了土壤容重对其入渗能力的影响,为土壤改良和促进天然降水转化利用提供理论依据。结果表明,容重对土壤入渗能力有较大影响。试验土壤入渗能力随容重增大递减,3种典型土壤稳定入渗速率与容重均呈对数负相关,砂壤120min累积入渗量与容重呈幂函数负相关,中壤、黏壤则呈线性负相关。考斯加科夫入渗模型中,表征初始入渗速率的参数随容重增大递减,表征入渗能力衰减速度的参数则随容重增大递增,说明土壤初始入渗能力随容重增大递减,入渗能力衰减速度随容重增大递增。

Effect of soil bulk density on soil infiltration capacity was explored through simulated experiments. The experimental soils were different in soil texture （sandy loam, medium loam, clay loam） and bulk density by artificially altering composition of soil particle fractions. Infiltration capacity of experimental soils decreased along with increasing soil bulk density. The stable infiltration rate had negative correlation of logarithmic function with soil bulk density. The 120 min-cumulative infiltration showing negative correlation of power function with soil bulk density for sandy loam, and negative linear correlation for medium loam and clay loam. The parameter of Kostiakov infiltration equation which meaned initial infiltration rate decreased along with increasing soil bulk density, and the other parameter which meaned infiltration decaying rate increased. The results showed that the capacity of initial infiltration rate went down and the infiltration decaying rate went up along with increasing soil bulk density. The results provided the theoretical basis for soil improvement and rainfall utilization.