渭-库绿洲耕层土壤养分空间变异及影响因素分析

Spatial Variability of Tillage Layer Soil Nutrients and Its Affecting Factors in Weigan-Kuqa River Delta Oasis

【目的】了解耕层土壤养分空间分异规律对农田土壤合理施肥和防治土壤退化具有重要的现实意义。【方法】基于野外调查数据,采用统计分析方法对渭干河-库车河三角洲绿洲耕层土壤养分的空间分异特征和影响因素进行研究。【结果】(1)研究区耕层土壤有机质、全氮、碱解氮、有效磷和速效钾,都具有中度程度的空间变异性,变异程度由大到小依次为:有效磷>碱解氮>速效钾>全氮>有机质;(2)研究区内耕层土壤除速效钾具有中等空间相关性外,其它各项养分指标(有机质、全氮、碱解氮和有效磷)的块金效应都大于75%,在采样尺度内具有较弱的空间相关性,且受随机性因素如耕作、施肥、点源污染等人为活动的影响较大。【结论】各土壤养分指标在研究区域内呈现出东部和南部的含量较高,而西部和北部的含量较低,具有较为明显的空间分异特征;影响土壤养分的主要因素为地形条件、土壤电导率与土壤p H值。

【Objective】It is of great significance to understand the law of spatial variability of soil nutrients in tillage layer and to control soil fertility and prevent soil degradation.【Method】Based on the field investigation data of Weigan-Kuqa River Delta Oasis,the spatial variability characteristics of arable layer soil nutrients and its influencing factors were studied by using the statistical analysis method.【Result】（i）In the whole study area,the soil organic matter,total nitrogen,available nitrogen,available phosphorus and available potassium of arable layer all had moderate degree spatial variability,which were in the order of available phosphorus available nitrogen available potassium total nitrogen organic matter.（ii） In the study area,except for available potassium,the nutrient indexes（organic matter,total nitrogen,available nitrogen and available phosphorus） were all greater than 75 %,on the sampling scale,which had a weak spatial correlation affected by random factors such as cultivation,fertilization,point source pollution and other human activities.【conclusion】The nutrient contents in the eastern and southern parts of the study area were higher than that in the west and the northern part,and the spatial variability was obvious.The main influencing factors of the soil nutrient were the terrain conditions,soil conductivity and soil p H value.