Establishing management zones of soil sulfur and micronutrients for sustainable crop production

Abstract

Deficiency of nutrients in agricultural soils of the world is one of the major factors of soil degradation. The deficiency of nutrients especially sulfur (S) and micronutrients in different soils affect global crop production. Delineation of soil management zones (MZs), by understanding spatial distribution of soil parameters, could be an efficient way for devising strategies for effective nutrient management and sustainable crop production. In this study, we aimed at creation of soil MZs for ameliorating S and micronutrients deficiencies in the Narmada River basin (NRB), an important agricultural area of central India. We collected 5,984 geo‐referenced top layer (0–15 cm) soil samples from the NRB, India, and analyzed for soil acidity (soil‐water suspension), electrical conductivity (soil‐water suspension), soil organic carbon (Walkley and Black carbon), phyto‐available S (0.15% calcium chloride [CaCl2] extractable), and phyto‐available (diethylene triamine penta acetic acid extractable) micronutrients namely zinc (Zn), copper (Cu), manganese (Mn), iron (Fe), and boron (B) (hot‐water‐soluble). The values of studied soil parameters varied widely with coefficient of variation values ranging from 11.0 to 74.9%. Pearson's correlation coefficient analysis revealed significant correlations among the soil parameters. Geostatistical analysis revealed exponential, pentaspherical, K‐Bessel, and circular best‐fit semi‐variogram models for different soil parameters with moderate to strong spatial dependence. About 41.2, 78.6, 10.1, 2.70, and 32.6% of the area of the NRB had a deficit concentration of phyto‐available S, Zn, Fe, Mn, and B, respectively. The principal component analysis and fuzzy c‐means clustering produced five MZs. The produced MZ maps could be utilized for prioritization of nutrients supply and adoption of zone‐specific soil nutrient management strategies in order to achieve sustainable crop production in the NRB of India.