压砂地土壤导水特性空间格局及影响因子

采用10 m×10 m网格布点的方式对宁夏压砂田0~10 cm和10~20 cm深度下土壤饱和导水率(Ks)及其相关因素的空间变异规律进行研究。经典统计结果表明:2个采样深度下土壤容重、总孔隙度和毛管孔隙度表现为弱变异,饱和含水量和土壤有机质含量表现为中等变异;0~10 cm深度下K_s表现为中等变异,10~20 cm深度下K_s表现为强变异;10~20 cm深度下土壤各种性质的平均值均大于0~10 cm深度。Pearson相关性分析可知,影响K_s的主要因素是毛管孔隙度,其次为容重、总孔隙度、饱和含水量和有机质含量。地统计结果表明,0~10 cm深度下K_s表现为纯块金效应,主要受随机性因素的影响,10~20 cm深度下K_s主要受结构性因素的影响;在2个采样深度下容重主要受随机因素的影响。从空间分布图可以看出,2个采样深度下K_s和容重存在高度的负相关关系,与饱和含水量、总孔隙度和毛管孔隙度存在高度的正相关关系。

Spatial variability of soil saturated hydraulic conductivity and its influencing factors in the gravel mulched field of Ningxia

Spatial variability of soil saturated hydraulic conductivity and its influencing factors could lay the scientif-ic basis for soil water and soil desiccation management in mulched field .The classical and geological statistics were com-bined to identify the spatial variability of soil saturated hydraulic conductivity and its influencing factors at 0~10 cm and 10~20 cm depths with 10 m × 10 m grids .The classical statistics indicated that at the 0~10 cm and 10~20 cm depths the soil bulk density ,total porosity and capillary porosity showed light variation ,saturation moisture content ,soil organic matter showed moderate variation ,while soil saturated hydraulic conductivity had moderate and wide variation at the 0~10 cm and 10~20 cm depths ,respectively .The capillary porosity was the key factors influencing saturated hydraulic conductivity by Pearson correlation analysis ,followed by bulk density ,total porosity ,saturation moisture content and soil organic matter content .The geological statistics indicated that saturated hydraulic conductivity at the 0~10 cm depths was basically affected by random factors with pure nugget variograms ,while at the 10~20 cm depths primarily affected by structural factors .At the 0~10 cm and 10~20 cm depths ,the spatial variability of soil bulk density was mainly af-fected by random factors .According to the spatial distribution patterns ,saturated hydraulic conductivity was highly nega-tive correlated with bulk density ,while was high positively related to saturation moisture content ,total porosity and capil-lary porosity .