不同残膜含量对淡灰钙土水分入渗过程的影响

Study on influence of different agricultural residue film amounts on soil infiltration process of light sierozem

为探讨不同残膜含量对土壤入渗性能的影响,以银川平原淡灰钙土为研究对象,设置5组不同残膜量:0(T0)、100(T1)、200(T2)、400(T3)、800 kg·hm^(-2)(T4),利用一维垂直定水头入渗法,观测湿润锋运移规律和水分入渗过程,并利用4种入渗模型拟合土壤入渗过程,分析其适用性。结果表明,随残膜含量递增,在同一入渗历时内累积入渗量逐渐减小。当入渗时间为390 min时,与T0相比,T1～T4处理的累积入渗量分别减少4.7%、5.8%、6.3%、11%。在入渗同等时间内,残膜量越高其湿润锋运移距离越短。当湿润锋在土柱完成运移时,T0～T4处理分别耗时390、420、510、600、660 min,即随残膜含量的升高入渗时间延长。T0～T4稳定入渗速率分别为0.27、0.24、0.21、0.19、0.16 mm·min^(-1),入渗率随残膜含量的升高而降低。入渗模型拟合的R^2大小依次为通用经验模型>Kostiakov模型>Philip模型>Horton模型,通用经验模型适合描述含残膜土壤的水分入渗过程。研究表明残膜对淡灰钙土水分入渗存在抑制作用,其影响程度随残膜量增加而增大。

In order to explore the effects of different residual film amounts on the infiltration performance of soil water, five residual film treatments were conducted:0(T0), 100(T1), 200(T2), 400(T3), 800 kg·hm-2(T4)with the object of light sierozem in Yinchuan Plain.One-dimensional vertical constant head infiltration method was used to observe soil water movement under different amounts of residual film. We also simulated soil water infiltration process with 4 infiltration models and evaluated their applicability. The results showed that the cumulative infiltration decreased with the increase of the residual amounts. When the infiltration time was 390 min, the cumulative infiltration decreased by 4.7%, 5.8%, 6.3%, 11% for T1~T4 treatments contrast to T0, respectively. The migration distance of dripping wet front in the same time was shorter with the increasing of the residual amounts in the soil. The infiltration time of T0~T4 treatment were 390,420, 510, 600, 660 min at the end time of infiltration, respectively, which indicated that infiltration time was prolonged with the increasing of residual amounts. The stable infiltration rate of T0~T4 was 0.27, 0.24, 0.21, 0.19, 0.16 mm·min-1, respectively, which indicated infiltration rate decreased with the increasing of residual amounts. The R2 of the fitted infiltration models was as follow:Common experienced model>Kostiakov model>Philip model>Horton model. The common experienced model was more effective than the other models, and it was suitable to describe the soil water infiltration process with residual film. The study indicated that the agricultural residue had a hindering effect on soil water infiltration for light sierozem in Yinchuan Plain,and the influence degree would aggravate with the increase ofthe residual amounts.