毕节市耕地土壤pH的空间变异特征与影响因素

Spatial Characteristics and Influential Factors of Arable Soil pH in Bijie, Guizhou

为了探讨耕地土壤pH的空间变异及影响因素,以贵州省毕节市为研究区域,开展了耕地土壤pH的实地监测调查,获取了各监测点的空间位置和属性数据。结合地统计学和GIS方法,探讨了耕地土壤pH的空间变异特征。结果表明:毕节市0~10 cm层耕地土壤pH分布于5.12~9.20,土壤pH最优插值模型:趋势指数为1,插值模型为有理二次方程式,块金值与基台值之比为65.10%,表现出中等的空间相关性,说明结构性因素(自然因素)对0~10 cm层耕地土壤pH影响较大。在不同母质中,耕地土壤pH从小到大为:基性岩类、砂页岩类、河流冲积物、碳酸盐岩类、紫色岩类、泥质岩类、石英岩类。在不同土壤类型中,耕地土壤pH由小到大为:6.29、6.83、7.07、7.17、8.20,对应土壤类型分别为:石灰土、黄壤、黄棕壤、紫色土、棕壤。与地形的相关分析表明,耕地土壤pH与高程、坡度、坡向分别为中等相关、弱相关、中等相关。总的来说,耕地土壤pH受结构性因素(自然因素)和人为因素影响的共同作用。

It is important to explore soil pH variation and its influential factors for better crop management. In this study, a survey was conducted to obtain soil pH and the spatial parameters in Beijie of Guizhou. The spatial characteristics of soil pH was analyzed by using the methods of geostatistics and GIS. Results showed that soil pH ranged from 5.12 to 9.20. Soil pH optimal interpolation model was selected. The trend index of the model was 1, proved the model was rational. The ratio between nugget value and base value was 65.10%, showed a medium spatial dependence and suggested structural factors （the natural factors） had a greater influence on soil pH. Soil pH value showed an order of basic rocks 〉 sand shale 〉 fluvial deposits 〉 carbonate rocks 〉 purple rocks 〉 argillaceous rocks 〉 quartzites. Soil pH values showed were 6.29, 6.83, 7.07, 7.17 and 8.20 for limestone soil, yellow soil, yellow soil, purple soil and brown soil, respectively. The correlation analyses of soil pH with the elevation, slope, and slope aspect showed a moderate correlation, weak correlation and medium correlation, respectively. Overall, pH of arable land in Bijie is affected by both structural factors （natural factors） and human factors.