砾石覆盖粒径对土壤入渗过程的影响

(1.中国科学院 西北生态环境资源研究院, 兰州 730030; 2.中国科学院大学 中丹学院, 北京 100049)

砾石覆盖; 土壤水分; 入渗; 累积入渗量

Effects of Mulch Gravels with Different Sizes on the Process of Water Infiltration
LÜ Wencong1,2, QIU Yang1, XIE Zhongkui1, WANG Xinping1, WANG Yajun1

(1.Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730030, China; 2.Sino-Danish College, University of Chinese Academy of Sciences, Beijing 100049, China)

gravel mulch; soil moisture; infiltration; cumulative infiltration

备注

为了研究不同砾石覆盖粒径对土壤入渗过程的影响,选取一维垂直定水头法,进行了室内土柱模拟试验。试验设置5个处理:等效粒径为8.28,16.38,26.36,38.39 mm的砾石覆盖和无覆盖作为对照。结果表明:砾石覆盖改善了土壤水分入渗性能,湿润锋的运移深度和累积入渗总量明显增加。8.28,16.38,26.36,38.39 mm粒径砾石覆盖处理入渗总量分别增加了0.08,0.11,0.18,0.25倍,且入渗总量随砾石粒径的增大呈线性增加趋势。同时,砾石覆盖改变了土壤水分入渗速率,随着砾石粒径增大,土壤初始入渗率迅速增长,但稳定入渗率增长比较缓慢。8.28,16.38,26.36,38.39 mm粒径砾石覆盖处理初始入渗率分别显著增加了0.6,1.01,1.33,1.81倍(p<0.05); 稳定入渗率分别增加了0.07,0.08,0.16,0.18倍。与Horton和Philip入渗模型相比,Kostiakov模型可以更好地反映不同粒径砾石覆盖土壤水分入渗过程。总体来看,砾石覆盖显著改善了土壤入渗状况,且大粒径砾石覆盖土壤水分入渗效果最佳。因此,建议在干旱和半干旱区优先选择较大粒径砾石覆盖作为农业水保措施。
In order to study the effect of mulch of gravels with different sizes on the soil infiltration process, an one-dimensional vertical constant head method was selected to conduct indoor soil column simulation experiments. The following five treatments were investigated: 8.28 mm, 16.38 mm, 26.36 mm, 38.39 mm equivalent particle-sized gravel mulch and no gravel mulch as a control(CK). It was found that gravel mulch improved the soil water infiltration performance, and the migration depth and total infiltration of the wet front increased significantly. The total infiltration of 8.28 mm, 16.38 mm, 26.36 mm, 38.39 mm particle-sized gravel mulching treatment increased by 0.08, 0.11, 0.18, and 0.25 times, respectively, and the total infiltration increased linearly with the increase of the particle-sized of the gravel. At the same time, gravel mulch changed the soil water infiltration rate. As the size of the gravel increased, the initial soil infiltration rate increased rapidly, but the stable infiltration rate increased slowly. The initial infiltration rates of the 8.28 mm, 16.38 mm, 26.36 mm, 38.39 mm particle-sized gravel mulching treatments increased significantly by 0.6 times, 1.01 times, 1.33 times, and 1.81 times(p<0.05); the stable infiltration rates increased by 0.07 times, 0.08 times, 0.16 times, and 0.18 times, respectively. Compared with the Horton and Philip infiltration models, the Kostiakov model could better reflect the soil moisture infiltration process of mulchof gravels with different particle sizes. In general, gravel mulch can significantly improve soil infiltration, and large-sized gravel mulch has the best effect on soil moisture infiltration. Therefore, it is recommended to choose the large-sized gravel as an agricultural water conservation measure in arid and semi-arid areas.