石泉县中部地区土壤微量营养元素空间分布特征

以石泉县研究区678个表层(0-20cm)土壤样品微量营养元素(Fe₂O₃、Mn、Zn、Cu、Mo、B)的实测含量为对象,采用地统计学与GIS相结合的方法,对土壤微量营养元素的含量及空间分布特征进行分析。结果表明:研究区土壤微量营养元素含量的平均值均高于全国平均值,Mn平均值低于区域背景值,但相差不大。趋势效应参数分析得出,Fe₂O₃、Zn、Cu、Mo、B宜取二阶,Mn宜取一阶;土壤Fe₂O₃、Mn、Zn、Mo含量的最佳半方差拟合模型为指数模型,Cu为球状模型,B为高斯模型;Fe₂O₃、Mn、Zn、Mo、B的块金效应小于25%,具有较强的空间相关性;Cu的块金效应在25%~75%之间,具有中等程度的空间相关性。空间变异主要受自然因素的影响,人类活动对其影响较小。六种土壤微量营养元素呈带状、斑块状分布,与区域地层构造展布方向基本一致。

Spatial distribution characteristics of soils micronutrients in central region of Shiquan county

Based on the six micronutrients(Fe₂O₃,Mn,Zn,Cu,Mo,and B)testing data of 678 surface soil samples in Shiquan county,the geostatistics and Arcgis were used to analyze the spatial distribution characteristics of micronutrients in surface soils(0~20cm).The results showed that the mean contents of Zn,Mo,B,Mn,Fe ₂O₃ and Cu in Shiquan county are higher than the national average,while Mn is lower than the regional background value,but the difference is not significant.According to the analysis of trend effect parameters,it is suggested that Fe₂O₃,Zn,Cu,Mo,B should be second-order,and Mn should be first-order.Best theoretical semivariogram model for Fe₂O₃,Mn,Zn and Mo is the exponential model,the spherical model is for Cu,and the Gaussian model is for B.The nugget-to-sill ratio of Fe₂O₃,Mn,Zn,Mo and B is less than 25%with strong spatial correlation.While Cu ranges from 25%to 75%with medium spatial correlation.Indicating they are mainly affected by the parent material factors,while human activities have little influence.The distribution of the six soils trace elements is zonal and patchy,which is basically consistent with the distribution direction of regional stratigraphic structure.