晋中盆地典型耕地厚度、土壤养分空间变异

旨在探究旱作区耕地土壤耕层厚度及土壤养分空间格局与变异规律。以晋中盆地典型耕地土壤为研究对象,运用地统计学方法对耕地耕层厚度及土壤养分的空间变异进行分析,土壤养分选取有机质、pH、有效磷、缓效钾4个指标。结果表明：（1）各个指标的空间自相关性都是随着距离的增加而减小;（2）有效磷的半变异函数最优模型为高斯模型,其他指标的最优模型均为指数模型。各指标的块金系数由大到小依次为：有机质>有效磷>pH>耕层厚度>缓效钾;（3）耕层厚度、有效磷均为西北高东南低的空间格局,缓效钾为东北高西南低,有机质为西南高东北低,pH除北洸乡偏低外均偏高。地统计方法能良好地描述土壤性质的空间分布和变异特征,各土壤性质的空间变异过程中随机性与结构性并存,并且随机性均小于50%。

Thickness and Soil Nutrients of Typical Cultivated Land in Jinzhong Basin: Spatial Variation

The paper aims to explore the spatial pattern and spatial variation rule of cultivated land thickness and soil nutrients in drying farming region. Taking typical cultivated soil in Jinzhong basin as the research object, we analyzed the spatial variation of thickness of cultivated layer (TCL) and soil nutrients by geostatistics method, with soil organic matter (SOM), pH, available phosphorus (AP) and slow-effect potassium (SK) as the soil nutrients indexes. The results showed that: (1) the spatial autocorrelation of each index decreased with the increase of distance; (2) the optimum semivariance model of AP was Gaussian model, and the optimum semivariance model of other indexes was exponential model; the ratio of Nugget to Sill of each index was in order from large to small: SOM>AP>pH>TCL>SK; (3) the spatial pattern of TCL and AP had the tendency with higher in southeast and lower in northwest, SK had spatial pattern with higher in northeast and lower in southwest, SOM had spatial pattern with higher in southwest and lower in northeast, pH was high in whole study area except Beiguang. In conclusion, geostatistical method can describe the spatial pattern and variation characteristics of soil properties well; in the process of spatial variation of soil properties, the randomness and structure coexist, and the randomness is less than 50%.