山西襄汾农田土壤磁化率和养分空间变异性

Spatial Variability of Soil Magnetic Susceptibility and Nutrients in Xiangfen,Shanxi,China

应用地统计学方法研究了山西省西南部襄汾县农田土壤的环境磁学和养分特征。结果表明:土壤低频磁化率、高频磁化率、频率磁化率、pH值、有机质、全氮和全钾平均含量分别为92.54×10-8 m3.kg-1、86.93×10-8m3.kg-1、6.03%、8.26、1.94%、1.02g.kg-1和2.39%;变异函数分析显示,土壤低频磁化率的空间相关距离最大为14.33km,说明在一个较大的距离范围内存在空间相关性;块金系数比为23.41%,说明土壤磁化率主要取决于土壤母质、土壤性质、地形等结构因素。耕作和施肥等人为活动虽对土壤磁化率有一定的影响,但未改变其原有空间结构。本结果揭示土壤磁化率和养分的空间分布规律,为农田土壤环境质量评价和管理提供重要依据。

Spatial variability of soil magnetic susceptibility and nutrients in Xiangfen, located in southwest of Shanxi province, were investigated with geostatistics methods. The results showed that, the average of soil low frequency magnetic susceptibility, high frequency magnetic susceptibility, frequency dependent magnetic susceptibility, pH, organic matter, total nitrogen and total potassium were 92.54×10-8m3.kg-1 , 86.93×10-8m3.kg-1, 6.03%, 8. 26, 1.94%, 1.02 g.kg-1 and 2.39%, respectively; the semivariance analysis showed that soil low frequency magnetic susceptibility spatial correlation distances were 14.33 km. The Kriging method was applied to calculate the unobserved points and to generate the contour map. The ratio of nugget/sill was 23.41%, indicating that the spatial variability of the soil magnetic susceptibility was mainly affected by soil parent materials, soil properties and topology factors etc. Cultivation and fertilizer affected soil magnetic susceptibility, but they didn＇t change soil magnetic susceptibility intrinsic structure.