Soil Nutrients Distribution in Arid Agriculture Soils of Selected Taluks of Koppal District, Karnataka, India

Abstract

Soil is a vital resource that supports agricultural productivity through nutrient cycling, carbon sequestration, and essential ecosystem services. Soil fertility, governed by physicochemical properties like pH and nutrient availability, directly influences crop yield and sustainability. Modern assessment methods, including nutrient index and statistical analyses, are crucial for managing soil health and addressing nutrient deficiencies. This study assessed the fertility status of soils from three representative taluks of Koppal district, Karnataka, using descriptive statistics, nutrient index, and correlation analysis of key soil properties. 20 surface soil samples (0-30 cm depth) were collected from fields in Kushtagi, Kanakagiri, and Gangavathi taluks and analyzed for pH, EC, organic carbon, available N, P, K, S, exchangeable Ca & Mg, and micronutrients- Cu, Zn, Mn, and Fe. Soil pH and EC indicated neutral to alkaline and non-saline soils, with low OC levels. Nutrient index (N.I) values indicated low fertility in OC, N, P, and K; medium fertility in Ca, Mg, Zn, and Fe; and high status for S, Cu, and Mn. Correlation analysis revealed the strong positive relationships with several secondary and micronutrients and some negative correlations of Mn with pH and OC. The results highlight organic carbon, N, P, and K as primary constraints in those taluks and underline the need for management practices for the nutrient deficiencies.