豫西典型烟田土壤颗粒组成的空间变异性分析
Spatial Variability of Soil Particle Composition Based on Geostatistics
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摘要: 空间变异性研究有利于认识土壤养分的空间分布特征与生态过程的关系。本研究旨在系统量化研究区域土壤颗粒组成的空间变异性和相关性,以揭示土壤颗粒组成的空间分布特征。采用“网格法”取样(100 m×100 m),利用地统计学方法分析了平顶山典型烟区土壤颗粒组成的空间相关性。结果表明,黏粒和砂粒的最优半方差函数为球状模型,粉粒为指数模型;砂粒和黏粒具有较强的空间相关性和较好的结构性,粉粒具有中等空间相关性,结构性较差;三者的各向异性均较小,黏粒的趋势效应最强,空间变异性最大,砂粒趋势性弱,且空间变异性小,粉粒的趋势效应不明显。Kriging 插值显示,该区土壤砂粒含量以北部较高,西南部较低,粉粒和黏粒的分布与砂粒呈相反的趋势;该研究区壤土占绝大部分,粘壤土仅在西南角有小块分布。Abstract: Spatial variability of soil nutrients provides useful information for improving agricultural practices and ecological management. The objectives of this study were to (i) quantify the spatial variability and spatial correlation of soil particle composition across areas and (ii) generate contour maps for the soil particle composition to reveal the characteristic of distribution. Grid sampling method (100 m×100 m) and geostatistics were applied to analyze the spatial distribution of soil particle composition in tobacco plantation field in Pingdingshan. The results showed that, sample variograms of soil particle composition were fitted well by spherical and exponential models, respectively. Sand and clay had a strong spatial correlation, good structural, while the silt with a moderate spatial correlation and bad structural. The anisotropic of three components of soil particle composition were little. The clay had the strongest of trend effect and the biggest of spatial variability, sand had little spatial variability with certain trends in effects, silt had a little trends effect. Kriging interpolation results showed that the high sand content in the north, while the lower in south-west; the distribution of clay and silt content was converse to sand. In the study area, the most account of the area was loam, the clay loam had small distributed only in the southwest corner.