乌鲁木齐县蔬菜地土壤养分空间变异研究

以乌鲁木齐县蔬菜主产区的三个乡为例,采用GIS与地统计学相结合的方法对其耕层土壤(0~20 cm)的有机质、全氮、速效氮、速效磷、速效钾等5种养分要素的空间变异特征进行分析。结果表明:全氮变异函数曲线的理论模型能很好地符合球状模型;有机质、碱解氮、速效磷、速效钾的变异函数曲线则符合线性无基台模型。有机质、速效磷和速效钾具有很强的空间相关性,说明受母质、地形、土壤类型等自然的结构性因素影响较大;碱解氮具有中等的空间相关性,说明对施肥、作物、管理水平等随机因素引起的空间相关性起很大作用;全氮的空间相关性很弱,说明人为活动严重削弱了结构性因素造成强的自相关作用。

Study on Spatial Variability of Nutrients in Vegetable Soil in Urumqi

Geostatistics combined with GIS was applied to analyze the spatial variability of soil nutrients in topsoil(0～20 cm) in Urumqi County of Xinjiang.Soil nutrient data in this study including available N(alkaline hydrolyzing nitrogen),pure N,available K,available P and organic matter were analyzed. The results showed that the semivariograms of soil nutrients were best described by linear without sill model except for that of pure N,which was best fitted by spherical model.Soil organic matter、available P and available K presented strong spatial dependence,soil available N moderate spatial dependence,and soil pure N weak dependence.The spatial variability of organic matter、available P and available K was mainly produced by structural factor,while that of available N and pure N was primarily caused by random factor.However,their spatial heterogeneity degree was different :the degree of available N was higher,and that of pure N was lower.