宁夏固原地区土壤地球化学背景值分析

土壤背景值反映了一定范围内自然环境与人类活动作用下元素指标含量的本底值。依据宁夏固原地区1∶25 万土地质量地球化学调查取得的2 638件土壤样品,利用遍历循环迭代剔除和统计分析方法,得到了研究区表层土壤中53项元素的地球化学背景值和特征参数。通过与中国表层土壤丰度对比,发现研究区Cd、S含量明显高于全国表层土壤丰度,但处于安全限值内; 不同地貌类型下的元素含量差异不仅受成土母质、成壤环境等外部自然条件的影响,也反映了人类活动对土壤环境的扰动。研究可为农业可持续开发与合理利用提供较为可靠的数据支撑。

Analysis of soil geochemical background value in Guyuan area of Ningxia

The soil background value reflects the background value of element index content under the influence of natural environment and human activities in a certain area. Based on 2 638 soil samples obtained from the 1∶250 000 geochemical survey of land quality in Guyuan of Ningxia, the authors in this paper obtained geochemical background values and characteristic parameters of 53 element indexes, by using the methods of iterative elimination and statistical analysis. Compared with the national soil abundance, the contents of Cd and S are significantly higher than the national topsoil abundance value, and they are within the safety limit. The difference of element index content under geomorphic types is not only affected by external natural conditions such as soil forming parent material and soil forming environment, but also reflects the disturbance of human activities to the soil environment, which provides reliable data for the sustainable development and rational utilization of agriculture.