| Changes in the soil environment affect the movement of water in the soil.To analyze the effect of farming methods on the development and change of soil preferential flow in the field,this study takes the sugarcane field of typical farmland in Guangxi as the research object.Through soil column infiltration simulation experiment,combined with image morphological analysis,hue segmentation,numerical simulation,statistical analysis,etc.,this study explores the process and development degree of soil preferential flow in sugarcane fields under different farming methods and reveals the influence of ridge tillage,no-tillage,and straw-covered sugarcane on preferential flow in sugarcane fields.The results of the study can provided some theoretical support for further improving the water and fertilizer utilization efficiency of sugarcane fields and realizing the improvement of sugarcane quality and income.The results of this study were as follows:（1）Under the same external water supply conditions,the dyeing morphology of the ridged sugarcane field decreases significantly with the increased of soil depth.The average dyed area ratio of the soil vertical section was the smallest（12.43%）.The average value of the variation coefficient of dyeing morphology is 0.83,which was larger than that of straw mulching and no-till sugarcane fields.The vertical stained morphological images of straw-covered sugarcane fields were finger-like and lump-like.With the increase in soil depth,the staining morphology of no-tillage sugarcane fields shows a crack-like differentiation phenomenon,and the average maximum infiltration depth was 27.71 cm,which was 1.67times and 1.15 times that of ridge tillage and straw-covered sugarcane fields,respectively.No-tillage sugarcane field has the shortest time to reach saturation（T=400 min）,and the average outflow was 28.94 mL,which was significantly different from ridge tillage（15.54mL）and straw-covered sugarcane field（19.62 mL）（P<0.05）.Its preferential flow moves faster.（2）The rapid change degree of ridge-cultivated sugarcane field accounts for 4.97%of the soil depth at a depth of 10 cm,which was significantly different from that of straw mulching and no-tillage sugarcane fields（P<0.05）.The average fractal dimension of the straw-covered sugarcane field was 0.85,which was 1.15 and 1.27 times that of the long-cultivated sugarcane field and the no-tillage sugarcane field,respectively.No-tillage sugarcane field active degree preferential flow average was 55.14%,which was significantly different from straw-covered sugarcane field（30.10%）and ridge sugarcane field（46.03%）（P<0.05）.The preferential flow of rapid change,secondary active and active has the greatest impact on the development of preferential flow in ridge tillage,straw mulching,and no-till sugarcane fields,respectively.（3）In the whole 0-50 cm soil space,the average water content（27.15%）in the early stage of ridge-cultivation sugarcane field was the largest.Its bulk density（1.62 g·cm-3）was1.13 and 1.02 times that of straw mulching and no-till sugarcane fields,respectively.The average sand content of the no-tillage sugarcane field was 38.30%,which was higher than that of the other two farming methods.The average saturated hydraulic conductivity of the no-tillage sugarcane field was the largest(0.002 cm·s-1)within the soil depth range of 20-50 cm.The average soil organic matter(27.47 g·kg-1),total phosphorus(0.39 mg·g-1)and total nitrogen(0.29 mg·g-1)contents of straw-covered sugarcane fields were higher than that of ridge tillage and no-tillage sugarcane fields.The change of soil environmental chemical properties under the influence of the farming method has the most significant effect on the preferential flow of sugarcane soil. |
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