DTPA-Extractable Micronutrients and Their Correlation of Soil Properties of Waghodia, Vadodara District, Gujarat

Abstract

Seventy-five soil samples from five pedons of the Instructional Farm, Parul University, Waghodia (Vadodara), were evaluated to determine the vertical distribution of DTPA-extractable micronutrients (Zn, Cu, Fe, Mn, and B) and their association with major soil properties. Soil pH, CaCO₃, organic carbon, and texture significantly influenced micronutrient availability. Zinc ranged from 0.01–0.27 mg kg⁻¹, with more than 80% of surface horizons deficient (<0.6 mg kg⁻¹), showing a clear decrease with depth. Copper (0.20–2.10 mg kg⁻¹) remained adequate in all pedons, while iron (0.97–23.89 mg kg⁻¹) was also largely sufficient relative to the 4.5 mg kg⁻¹ critical limit. Manganese (2.90–53.36 mg kg⁻¹) was adequate in most pedons except P5, whereas boron (0.02–0.12 mg kg⁻¹) showed widespread deficiency, with over 85% of samples below the 0.5 mg kg⁻¹ threshold.

Micronutrient availability generally declined with depth and was strongly negatively correlated with soil pH and CaCO₃, indicating reduced solubility under alkaline conditions. Organic carbon and clay exhibited positive correlations with most micronutrients, highlighting their role in complexation and retention. Overall, the soils were moderately to strongly alkaline, varied from sandy loam to clay in texture, and displayed deficient levels of Zn and B, indicating the need for targeted micronutrient management for sustainable crop production.