Characters and Influencing Factors of the Distribution of Cultivated Available Soil Fe, Mn, Cu and Zn in Xichang City, Sichuan Province, China

Exploring the spatial distribution of available soil micronutrients can provide a solid foundation for scientifically formulated fertilizer. We investigated the characteristics and influencing factors of available micronutrients in cultivated soil in Xichang City Sichuan Province, China. Soil samples (302) were collected from the cultivated soil, and the contents of available Fe, Mn, Cu and Zn were analyzed respectively. Descriptive statistics and geostatistics were used to analyze the data. The Kriging method was applied to calculate the unobserved points and was used to generate the contour map. The ANOVA was used to study the influencing factors. The mean values of available Fe, Mn, Cu and Zn were 37.62, 2.89, 3.47 and 14.80 mg·kg-1 respectively, which were at rich level or at medium level. The available micronutrient contents took on medium spatial correlation, affected by random factors and structural factors. The spatial distribution of the micronutrients was all belt-shaped as a whole and showed significant differences. Topology, parent materials, irrigation water, land use types, pH and organic matter contents had significant effect on the micronutrient availability to different extent.