土地利用和初始含水量对琼东南黄色砖红壤水分入渗的影响

Impacts of Land Use Patterns and Soil Initial Water Contents on Soil Water Infiltration of Yellow Latosol in Southeast Hainan Island

采用环刀法,测定了琼东南万宁兴隆地区典型黄色砖红壤上不同土地利用及不同初始含水量下的土壤入渗过程,分析对比了3种常用入渗模型的适宜性。结果表明,不同土地利用方式之间,胡椒园土壤初始入渗率、稳定入渗率和1 h累积入渗量等入渗指标均明显高于自然草地土壤和咖啡园土壤,入渗性能最佳;虽然自然草地的稳定入渗率和1 h累积入渗量等指标略高于咖啡园土壤,但二者整体入渗性能相差不大。造成上述入渗性能差异的原因与不同种植园对土壤改造程度不同而引起土壤质地变化有关。不同初始含水量对土壤入渗过程也有显著影响,随土壤初始含水量增加,初始入渗率、稳定入渗率和1 h累积入渗量等指标均呈下降趋势,表明土壤越湿润,土壤入渗性能也相应减弱。Kostiakov模型和Horton模型对不同土地利用和初始含水量下的土壤入渗过程拟合效果较好,可作为今后黄色砖红壤土壤入渗的适宜模型。本研究结果可为琼东南黄色砖红壤地区农业生产及相关灌溉策略制定提供参考。

In this study, a cutting ring infiltration method was used to quantitatively measure the infiltration processes of three different land use patterns under two soil initial water contents from yellow latosol in southeast Hainan Island. Fitting analysis of infiltration processes was also conducted based on three normal infiltration models. The results showed soil water initial infiltration rate, stable infiltration rate and 1h cumulative infiltration of black pepper plantation were obviously higher than those in grassland and coffee plantation, hence the infiltration capacity of black pepper plantation was the best. Despite soil water stable infiltration rate and 1 h cumulative infiltration of grassland were slightly higher than those of coffee plantation, the overall performance of infiltration capacity between the two land use patterns were almost the same. The infiltration capacity difference among the three land use patterns was attributed to soil texture changes induced by land transformation before crop culturing. Meanwhile, as soil initial water content increased, initial infiltration rate, stable infiltration rate and 1 h cumulative infiltration in the three land use patterns all decreased, indicating soil infiltration capacity reduced with the soil moisture increasing. In addition, the soil infiltration processes were better fitted by Kostiakov and Horton infiltration model than by Philip model, which made the two models suitable for describing soil infiltration in yellow latosol area. Results of this study could be used as references for agricultural production and irrigation strategies making in yellow latosol area of southeast Hainan Island.