丘陵区不同土地利用类型紫色土入渗特征研究

Study on Soil Infiltration Characteristic of Different Land Utilization Types in Purple Soil Hilly Region

对三峡库区4种土地利用类型下紫色土入渗特征进行了研究。结果表明,农林混作型耕地与传统农耕地相比,砂粒含量增加21.37%,粉粒含量和粘粒含量分别减少11.63%和4.14%,其土壤总孔隙度和非毛管孔隙度是4种土地利用类型中最高的,分别为45.80%和8.96%;4种土地利用类型土壤入渗速率随时间变化呈幂函数关系,土壤稳定入渗率差异明显,表现为竹林地(55.89 mm/h)>农林混作型耕地(5.91 mm/h)>园地(2.71 mm/h)>传统农耕地(1.87 mm/h);农林混作型耕地达到稳渗时间比传统农耕地长70 min,稳定入渗率是传统农耕地的3.16倍,能够延缓地表径流产生,增加土壤水分入渗,可以在三峡库区范围内推广;紫色土入渗能力与砂粒含量、总孔隙度及非毛管孔隙度呈正相关关系,与粘粒含量、容重、初始含水量呈负相关关系。

Based on the research and analysis of purple soil infiltration characteristics under four land utilization types in Three Gorges reservoir region, results show that： Compare to traditional farmland, the sand content of tree-crop intercropping land increases 21.37%, its silt and clay content decreases separately 11.63 % and 4. 14 %, its overall porosity and non-capillary are 45.80% and 8.96 %, which is the best of four land utilization types; The relationship between soil infiltration rate and time of four land utilization types can be expressed as Y=a X^-b. The stable infiltration rate has obvious imparity among four land utilization types, and the result is bamboo forest land （55.89mm/h） 〉 tree-crop intercropping land （5.91 ram/h） 〉orchard （2.71mm/h） 〉traditional farmland（1.87 mm/h） ;As the time to attain the stable infiltration rate, tree-crop intercropping land is 70 minutes later than traditional farmland, and the stable infiltration rate of the former is as 3.16 times as the latter, these show that tree-crop intercropping land can postpone process of runoff yield and increase moisture infiltration into soils, so it can be popularized in the scope of Three Gorges reservoir region. The ability of purple soil infiltration assumes the positive correlativity with sand, overall porosity and non-capillary, with clay, bulk gravity and the initial moisture has the inverse correlations.