| In order to explore the effects of agricultural tillage methods on the characteristics of preferential flow in field soil and soil water movement,the sugarcane field in Guangxi was taken as the research object,on the basis of obtaining the original soil column,through the experiments of dyeing,slicing and infiltration simulation of the soil column,combined with the methods of image morphological analysis,simulation and multivariate statistical analysis,to systematically study the effects of no-tillage and ridge tillage on the characteristics of soil preferential flow in sugar cane fields,and to clarify the response of soil water infiltration movement to preferential flow,so as to provide some theoretical basis for improving appropriate tillage methods and guiding sugarcane production regulation.The results of this study are as follows:（1）No-till sugarcane field soil the dyeing is given priority to with finger shape distribution,dyeing gradually reduce with the increase of soil depth,soil vertical section average total coloring area than is the largest（70.91%）.The staining distribution of sugarcane field in ridge tillage was mainly clumps,and the staining decreased significantly with the increase of soil depth.The average total staining area ratio of vertical profile was the lowest（51.66%）,and there was a significant difference（P<0.05）.The average fractal dimension and average compactness of no-tilled sugarcane field were 1.684 and 0.369,respectively,which were significantly higher than those of furrow field（P<0.05）,and the average turning radius index was the smallest（1.191）,which was significantly different from those in ridge-tilled sugarcane fields（P<0.05）.Ridge tillage sugarcane field average coefficient of variation is higher than zero tillage,and in the 0-10 cm and 30-50 cm soil depth range and no-till sugarcane field have significant difference（P<0.05）.No-till sugarcane field in soil space dyed form more gathered,preferential flow phenomenon is more significant.（2）Compared with non-tillage sugarcane field,the average total number of preferential paths in ridge tillage sugarcane field and the average number of preferential paths under different diameter classes（<0.5 mm,0.5-1 mm,1-2.5 mm and≥2.5 mm）increased by 22.84%,50.00%,24.49%,22.35%and 22.63%,respectively.The variation and complexity of preferential paths were significantly increased in ridge cultivation sugarcane field（P<0.05）,the soil staining morphology was relatively irregular（mean roundness rate was 0.236）,and the degree of adjacency of staining area was scattered（mean proximity index was 0.458）.The average specific surface area,anisotropy and connectivity density of preferential paths in no-tillage sugarcane field were 30.588 cm-1,0.864 and 1178.588 cm-3,respectively,which were significantly different from those in ridge tillage sugarcane field（P<0.05）.Ridge tillage sugarcane field preferential paths number is more,but the preferential paths higher level of distortion and connected degree is low,to some extent,affected the preferential flow.（3）The average saturated water conductivity(0.080 mm·s-1),the average stable mass flow rate(0.317 g·s-1)and the average mass flow rate(0.330 g·s-1)of sugarcane field under no tillage were all higher than those under ridge tillage,but the average water content of sugarcane field under ridge tillage was the largest（23.81%）.The maximum effective volumetric flow velocity(0.96×10-5 m3·s-1)was found in no-tillage sugarcane field at 50 cm soil depth,while the minimum was found in furrow field(0.73×10-5 m3·s-1).The pore water pressure（400 Pa）in no-tillage sugarcane field was the minimum at 10 cm depth,while the pore water pressure（424Pa）in ridge tillage was the maximum.No-till sugarcane field water infiltration is relatively active,stable and rapid infiltration through the preferred path,preferential flow phenomenon is obvious. |
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