Trace Element Contents in Typical Soils in Shanxi Province

【Objective】 Trace elements in soil are essential for crop growth and food heath. Their bioavailability varies with various biotic and abiotic factors. This paper presents an analysis of trace elements in plough soil layer and its influencing factors in Shanxi province. 【Method】 Three representative counties with large cultivation areas of wheat, corn and millet were selected in the study. In each county, we took soil samples from 100 sites, and the contents of Fe, Mn, zinc and Se in each sample, as well as their relationship with pH, organic matter, soil type, and crop types, were analyzed and calculated. 【Result】 The average contents of Fe, Mn, Zn, and Se in all soil samples across the three counties were 30.42 g/kg, 626.55 mg/kg, 78.06 mg/kg, and 0.283 mg/kg, respectively. Contents of all elements varied spatially over the planting areas, with the highest content found in wheat-growing areas, followed by corn and millet fields. Trace elements in the three counties were mostly at medium or high levels, but some deficiencies were detected, particularly Fe in millet-growing areas. The contents of the four elements were significantly higher in litho, fluvo-aquic, fragmental, cinnamon and red clay soils than in brown, cultivated loessal, castno-cinnamon, and aeolian sandy soils. The trace elements were negatively correlated to pH and positively related to organic matter, both at significant levels. Correlation among the four trace elements themselves was positive, and multiple stepwise regression analysis showed that the combined effect of planting area, soil type, pH and organic matter, on Se were the highest, with the comprehensive interpretation rate being 47.9%. The variation in Mn content was affected by soil type and organic matter, with its comprehensive interpretation rate being 8.1%. 【Conclusion】 The contents of Fe, Mn, Zn and Se in the plough soil layer are at moderate level or above in most areas in Shanxi province. However, Fe supplementation and nutrient improvement in millet-growing areas are required. Se content is affected by environmental changes, while Mn content is comparatively stable. Overall, the contents of the four trace elements are highest in wheat-growing areas, followed by corn and millet fields.