Effects of plastic film mulching on spatial heterogeneity of soil preferential flow in ridge tillage farmland
Author:
Affiliation:
(1.GuilinUniversity ofTechnology，Guangxi Collaborative Innovation Center for Water Pollution Control and Safetyin KarstArea，Guilin Guangxi541004;2.Guilin University of Technology，Guangxi Key Laboratory of Environmental Pollution ControlTheory andTechnology，Guilin Guangxi541004;3.Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology for Science and Education Combined with Science and Technology InnovationBase，GuilinGuangxi541004;4.Guilin University ofTechnology，College of Environmental Science andEngineering，Guilin Guangxi541004)
In order to provide scientific support for further formulating efficient water and fertilizer strategies for ridgefarming field agriculturalproduction，combined field staining tracer experiments with indoor soil column water infiltrationexperiments，and the image morphologicalanalysis，simulated infiltrationanalysis，entropy weight analysis and gray system theory analysis were applied. The spatial heterogeneity characteristics of farmland soil preferential flow under ridge filmmulching andridge(control)planting measures were analyzed to clarify the spatial distribution and movement of farmland soil preferential flow under ridge film mulching measures. The relationship between preferential flow and soil water movement process in ridge field under the influence of film mulching measures was revealed. The results showed that under the same external watersupplyconditions，the water of ridge-mulching farmland was concentrated in the 0-10 cmsoil surfacelayer， and the distribution range was gradually decreased with the increase of soil depth. The complexity of soil dyeing was increased first and then decreased with the increase ofsoil depth. However，the water distribution of ridge planting farmland in the range of 10-30 cm soil depth showed a significant finger-like preferential flow differentiation phenomenon. At the sametime， the time for the soil to reach saturation in the ridge-mulched farmland was 1.36 times that of the ridge-mulched farmland. Theaverage soil column outflow per unittime(mass flow rateof 0.20g/s)wassignificantly( P<0.05)less than that of the ridge-mulched farmland(mass flow rateof 0.35 g/s)，and the degree of soil preferential flow was higher. Among the soilproperties，saturated hydraulic conductivity had the greatest influence on the degree of preferential flow. Compared with ridgeplanting，ridge planting could further reduce the occurrence and distribution of preferential flow in farmland soil space to acertainextent，reduce water leakage to deepsoil，and play a certain role in water storage and moisture conservation.