南疆果园滴灌条件下土壤盐分的空间异质性分析——以农十四师224团典型地块为例

Spatial Variability of Soil Salinity under Drip Irrigation Conditions in Orchard of Southern Xinjiang:A case Study on 224 Regiment of 14 Division

土壤盐渍化是制约干旱半干旱地区农业生产的主要障碍因子之一,在新疆,尤其是南疆,盐渍化更为严重。系统认识和掌握盐渍土的空间变异特征对于治理改良盐渍土和土壤盐渍动态变化研究具有重要意义。基于区域变量理论,在GIS和地统计学技术支持下,通过地统计学的半变异函数和Kriging空间插值,以南疆和田地区农十四师224团为研究区,定量分析了试验区内不同层次土壤盐分的空间变异特征。结果表明：140~180 cm土层土壤盐分含量半方差函数的理论分布模型属于指数模型,其它各层属于球状模型;各土层含盐量在一定的区域范围内具有空间结构特征,都呈中等强度空间自相关性;由kriging插值可知,各土层含盐量的空间分布主要表现为条带状伴有斑块状分布。总体来说,试验区土壤盐渍化与次生盐渍化的防治是近期农业管理中所必须考虑的重要因素。

Soil salinization is one of the main barriers in agricultural production in arid and semi arid areas,especially in southern Xinjiang.Understanding the characteristics of spatial distribution of saline soil is important in establishing strategies for soil salinity management.Geo-statistics,based on the regional variable theory,has been proved to be one of the most effective methods to analyze the spatial distribution and its variation law of soil properties.It is the foundation to well manage the soil and prevent the soil salinization for fully understanding the spatial distribution of soil salinity.In the present study,the spatial variability of soil salinity in different soil layers is studied by means of GPS,GIS,semivariograms of geo-statistics and Kriging method in 224 regiment of 14 division to quantificationally analyze the spatial variation of soil salinity in Experimental Area.The semivariogram of soil salinity 140-180 cm soil layers is best described by the Exponential model,and each layer left is best fitted by the Spherical mode1.Results indicate that soil salinity of each soil layer shows the moderate spatial variability and spatial autocorrelation resulting from compound impact of intrinsic and extrinsic factors,and the autocorrelation distance of each soil layer varies insignificantly.The spatial distribution maps of salt salinity interpolated by Kriging interpolation all show apparently strip and block.The entire plain has been basically free from soil salinization,and the prevention and secondary salinization are essential in farming practice management.