沙地土壤pH值、养分含量对微地形变化的响应

Effects of Micro-topography on Soil pH Value,Nutrient Content in Sandy Land

[目的]针对浑善达克沙地土壤pH值、碳、氮、磷含量的微地形变异性进行研究,系统分析浑善达克沙地不同微地形条件下土壤营养物质含量的的变化规律,为浑善达克沙地环境建设和合理开发利用提供理论参考。[方法]以内蒙古锡林郭勒盟白音锡勒牧场境内的中国科学院内蒙古草原生态系统定位站长期围封的沙地样地为研究对象,测定坡位对土壤pH值、碳、氮、磷含量。[结果]不同坡位pH值平均值大小顺序为:阳坡>坡底>阴坡>坡顶;有机碳含量平均值大小顺序为:坡底>阴坡>阳坡>坡顶;全磷含量平均值大小顺序为:坡底>阴坡>坡顶>阳坡;土壤含氮量阴坡和坡底显著高于坡顶和阳坡。[结论]不同微地形条件下各层土壤pH值、全碳和全磷含量的变异系数均表现为阳坡和坡顶高于阴坡和坡底;同一坡位不同土层营养物质含量变异系数大小关系没有规律可循,因坡位和土层不同而表现出不同的大小关系。

[Objective]We aimed to study the effects of slope on soil pH value,carbon,nitrogen,phosphorus content in sandy land in order to reveal the variation of soil nutrients under different micro-topographical conditions,and provide a theoretical reference for environmental construction in sandy land.[Methods]The plots were selected from sandy land in Inner Mongolia grassland ecosystem research station（IMGERS）.The effects of micro-topographical position on pH value,carbon,nitrogen and phosphorus content of soil were investigated.[Results]The pH values in different micro-topographical position showed as：sunny slope〉slope base〉shady slope〉top of slope;The organic carbon content average showed as：slope base〉shady slope〉sunny slope〉top of slope;The content of phosphorus showed as：slope base〉shady slope〉top of slope〉sunny slope.Nitrogen content at the slope base and shady slope was higher than that at the top and sunny slope.[Conclusion]The variable coefficient of pH value,nitrogen,phosphorus content at top and sunny slope was higher than that at the base and shady slope.The variable coefficient of soil nutrient varied significantly among different micro-topographical positions.