容重对红壤条件下涌泉根灌水分入渗能力影响

为研究红壤地区土壤容重对涌泉根灌水分入渗能力的影响,以江西红壤为例,采用室内试验,研究了不同容重条件下红壤涌泉根灌水分运移及其分布特性。结果表明:容重对土壤入渗能力有显著影响。随着容重的减小,湿润锋、累积入渗量、入渗率均呈增大趋势,且容重越小,减小的幅度越大。湿润锋、累积入渗量以及稳渗率与土壤容重均呈幂函数负相关关系;对于同一深度土层,土壤容重越大,对应的土壤含水率越小,在水分再分布过程中容重对含水率分布的影响逐渐减弱。通过Kostiakov入渗模型表明,土壤初始入渗速率随容重增大而减小,且容重越大,入渗能力的衰减速度也越快。研究结果可为涌泉根灌技术在红壤地区的推广应用提供理论依据。

The Influence of Bulk Density on Water Infiltration Capacity in Red Soil Under Surge-root Irrigation

In order to explore the effect of soil bulk density on the water infiltration capacity under surge-root irrigation (SRI) in red soil regions, a experiment of water infiltration was carried out under different soil bulk density levels of red soil for SRI in soil bins. The results showed that the bulk density had a significant effect on soil infiltration capacity. With the decrease of soil bulk densities,wetting front migration, the cumulative infiltration and the infiltration rates showed increasing trends. The smaller the bulk density was, the greater decrease occurred. The wetting front migration, the cumulative infiltration and the steady infiltration rates and soil bulk densities were negatively correlated as power functions. For the same depth soil layer, the smaller the soil moisture content was observed in the larger the soil bulk density. The effect of bulk densities on the water content distribution was gradually weakened during the water redistribution process. The Kostiakov infiltration model showed that the initial infiltration rates of the soil decreased with the increase of bulk densities. Under the greater the bulk density, the infiltration capacity decreased more fastly. This research could lay the foundation for the popularization and application of SRI technology in red soil areas.