关中平原区土壤5种微量元素的空间变异及分布评价

Spatial variability and distribution of five soil micro-elements content in farmland of Guanzhong Plain

为了揭示黄土高原地区农田土壤微量元素空间变异规律及分布特征，选择陕西省扶风县揉谷乡新集村为试验区，在219hm^2耕地上用网格法采集364个耕层（O～20cm）土壤样品，对其5种微量元素B、Fe、Mn、Zn和Cu有效含量的空间变异进行地统计学分析，并结合Kriging插值结果对其不同级别含量的分布状况进行评价。结果表明，土壤有效B、Fe、Mn、Zn和Cu的理论半方差模型分别符合线性、指数、球状、指数和线性模型，有效B和Mn具有中等的空间相关性，有效Cu、Fe和Zn具有强烈的空间相关性；5种微量元素最大相关距离依次为：B、cu〉zn〉Mn〉Fe，最大相关距离为648～1855．1m；5种微量元素表现出条带状和斑块状空间分布；有效Fe、Mn、Zn和Cu的含量分布与土壤水分有关，有效B的分布与土壤酸碱度有关。

The paper is presented on spatial variability and distribution of 5 soil micro-element contents （available B, Fe, Mn, Zn, and Cu） in farmland of Guanzhong Plain. Total 364 top-layer （0- 20 cm） soil samples were taken by grid from 219 hm^2 farmland in Xinji village of Shaanxi Province and analyzed by Geotatistics method. Results indicated that the variogram of 5 micro-dement nutrients showed a linear model （B）, exponential model （Fe） ,spherical model （Mn）, exponential model （Zn） and linear model （Cu）. B and Mn had intermediate spatial correlation ranges, while Cu, Fe and Zn had sharp spatial correlation ranges. The order of longest correlation range in 5 micro-elements was B,Cu〉Zn〉Mn〉Fe （from 648m to 1855.1 m）. By using kriging method,the spatial distributions of 5 soil micro-element took on piece and speckle shape in study area,the spatial distributions of Fe, Mn,Zn,and Cu were connected with the moisture level,while available B was connected with the soil pH.