农田土壤入渗特性研究

以陕西杨凌一级阶地砂壤土和三级阶地粘壤土所选典型田块的双环入渗试验为基础，对不同土壤质地条件下的土壤入渗特性进行了研究。结果表明：两种土壤质地条件下描述其入渗过程的最优入渗公式为修正Kostiakov公式；土壤入渗试验合理的设计观测时间一级阶地砂壤土条件下不应小于90 min，三级阶地粘壤土条件下不应小于120 min；根据各入渗参数的最大相关距离，计算了典型田块入渗试验的合理测点数，一级阶地砂壤土和三级阶地粘壤土试验田块均为42个测点；可在一定程度上借助稳定入渗率f₀的变异特征描述土壤入渗性能和衡量土壤入渗能力，但同时还应考虑入渗参数k的空间变异特征。

Research on the soil infiltration characteristics in the field

Based on the double-ring infiltration experiments carried out in the selected fields of the first terrace and the third terrace with sandy loam and clay loam respectively in Yangling District, Shaanxi Province, China, the soil infiltration characteristics under different soil textures were studied. The results showed that the modified Kostiakov function was the optimal choice in describing the process of soil infiltration. The reasonable observing time of infiltration experiment was no less than 90 min in the first terrace with sandy loam and no less than 120 mins in the third terrace with clay loam. Based on the maximum correlation distance among the infiltration parameters, the reasonable sampling number was proved to be 42 for the selected fields in both the first terrace and the third terrace. The spatial variation characteristics of basic infiltration rate f₀ could be employed to describe the infiltration performance and to measure th e infiltration capacity of soil, and the spatial variation characteristics of the infiltration parameter k should also be taken into consideration. The study results could set the scientific foundation for a further study of soil infiltration characteristics.