基于色相分割的甘蔗地土壤优先流程度定量评价

Quantitative Evaluation of Soil Preferential Flow Degree in Sugarcane Fields Based on Hue Segmentation

在土壤优先流研究中广泛使用染色图像分析技术,优化提升染色图像分析方法,可促进深入研究土壤优先流运动过程,定量细化分析优先流的发育组成研究。以典型农地甘蔗地作为研究对象,通过野外染色示踪试验,利用色相分割技术,并结合分形与灰色系统理论对2种典型耕作方式(垄耕和免耕)的甘蔗地土壤优先流程度进行定量分析与评价。结果表明:在相同外部供水条件下,垄耕甘蔗地土壤空间内的优先流相对于免耕甘蔗地的枝状染色形态呈零散团块状和散点状,垄耕甘蔗地染色等级1、等级2和等级3的分形维数均随土层深度增加而减小。垄耕甘蔗地土壤表层(0—10 cm)内发生的“速变”程度的优先流是相同深度下免耕甘蔗地的12.0倍,免耕甘蔗地的“活跃”程度优先流平均占比值为67.4%,是垄耕甘蔗地(54.2%)的1.2倍。容重对垄耕甘蔗地优先流发育程度影响最大,优先流程度随容重的增加而降低,而免耕甘蔗地的饱和导水率对优先流发育程度影响最大,优先流程度随饱和导水率减小而降低。垄耕耕作方式会影响甘蔗地田间含水量,加快土壤表层的水流运动,降低深层优先流的发育,减少水分入渗,在一定程度上可以起到蓄水保肥的作用,并能为广西甘蔗种植产业的增产增量相关研究提供技术支撑。

The extensive use of dyed image analysis techniques in the research of soil preferential flow,optimization and improvement of dyeing image analysis methods,can promote in-depth study of the movement process of soil preferential flow,and quantitatively refine and analyze the developmental composition of preferential flow.Taking typical farmland sugarcane field as the research object,through field dyeing tracer experiment,using hue segmentation technology,combined with fractal and gray system theory,the preferential flow degree of sugarcane field soil in two typical farming methods(ridge and no-tillage)was quantitative analyzed and evaluated.The results showed that:under the same external water supply conditions,the preferential flow in the soil space of the ridged sugarcane field was scattered,clumpy and dot-like compared to the branch-like staining morphology of the no-tillage sugarcane field.The dyeing grade 1of the ridged sugarcane field,the fractal dimensions of 2 and 3 both decreased with the increase of soil depth.The preferential flow of“rapid change”in the top soil layer(0—10 cm)of ridged sugarcane field was 12.0 times that of no-tillage sugarcane field at the same depth,and the average percentage of preferential flow of“active”degree of no-tillage sugarcane field was 67.4%,which is 1.2 times that of ridged sugarcane land(54.2%).Bulk density had the greatest impact on the development of preferential flow in ridged sugarcane fields,and the degree of preferential flow decreased with the increase in bulk density.The saturated hydraulic conductivity of no-tillage sugarcane fields had the greatest impact on the development of preferential flow,and the degree of preferential flow decreased with decrease of saturated hydraulic conductivity.Ridge tillage affects the water content of sugarcane fields,speeds up the movement of water in the soil surface,reduces the development of deep preferential flows,reduces water infiltration,and can play a role in water storage and fertilizer preservation to a certain extent,can provide technical support for industry’s production increase and increase related research of sugarcane planting in Guangxi.