基于地统计学的山西省不同类型土壤有机质空间变异分析研究

Spatial Variability Analysis of Organic Matter in Different Types of Soil Based on Geostatistics in Shanxi Province

为了展示山西省不同土壤类型条件下耕层土壤有机质含量的空间变异性以及影响因素,实现土壤肥力高效利用,进一步指导农业生产方式改良以及精准施肥。本研究以褐土、黄绵土、栗褐土、栗钙土四种山西省常见土壤类型进行研究,分别选取区位临近的县市采样,得到耕层土壤有机质含量数据,采用GIS与地统计学方法相结合的方法,研究不同土壤类型的土壤有机质含量的空间变异性,通过对比从三种函数模型(指数模型、球状模型、高斯模型)中选取最优拟合模型,并采用最优拟合模型进行插值制图以及趋势分析。结果表明,褐土平均有机质含量最高,其块金系数为25%,具有较强的空间结构性;黄绵土平均有机质含量最低,其块金系数为50%,具有中等强度的空间结构性;栗褐土平均有机质含量仅次于褐土,其块金系数为49%,具有中等强度的空间结构性;栗钙土平均有机质含量略低于栗褐土,其块金系数为32%,具有中等强度的空间结构性。由以上分析结果可以看出,土壤类型是土壤有机质含量空间变异的重要影响因素,除此之外,海拔、地形地貌、人为活动等因素同样对有机质空间变异会产生一定的影响。本研究可以为提高山西省土壤肥力、精准施肥、改良农业生产措施提供依据。

To demonstrate the spatial variability and influencing factors of organic matter content in different soil types in Shanxi Province, achieve high-efficient use of soil fertility, and further guide the improvement of agricultural production methods and precision fertilization, the organic matter content data of cultivated soil samples were obtained from the neighboring counties and cities with four soil types including cinnamon soil, loess soil, chestnut brown soil and chestnut soil as test materials.The spatial variability of soil organic matter content was analyzed by GIS and geostatistical methods. The optimal fitting model was selected from three functional models (Exponential model, Spherical model, Gaussian model), and used for interpolation mapping and trend analysis. The results showed that the average organic matter content of cinnamon soil was the highest with the nugget coefficient as 25%, and it had strong spatial structure. The average organic matter content of loess soil was the lowest with the nugget coefficient as 50%, and it had medium-strength spatial structure. The average organic matter content of chestnut brown soil was next to that of cinnamon soil with the nugget coefficient as 49%,and it had medium-strength spatial structure. The average organic matter content of chestnut soil was slightly lower than that of chestnut brown soil, and its nugget coefficient was 32%. It also had medium-strength spatial structure. It was concluded that soil type was an important factor affecting the spatial variability of soil organic matter content. The factors such as elevation, topography and human activities also had a certain impact on the spatial variation of organic matter. This study could provide references for improving soil fertility, precision fertilization and agricultural production measures in Shanxi Province.