Correlation analysis of texture, physico-chemical properties and nutrient availability in red cotton-growing soils of Nagarkurnool District

Understanding the relationships among soil texture, physico-chemical properties, and nutrient availability is essential for sustainable cotton production. This study evaluated these interactions in irrigated and rainfed red cotton-growing soils of Nagarkurnool district, Telangana. A total of 120 soil samples were collected from shallow and deep soils at surface (0–15 cm) and sub-surface depths during the 2023 kharif season. Soils were analyzed for texture, pH, electrical conductivity (EC), organic carbon (OC), available N, P₂O₅, K₂O, and DTPA-extractable Zn, Fe, Mn, and Cu. Correlation analysis revealed that clay content strongly influenced micronutrient availability, showing significant positive correlations with Zn, Fe, Mn, and Cu across most soil groups. Soil pH exhibited significant negative correlations with micronutrients, indicating reduced availability under alkaline conditions. Organic carbon showed a strong positive relationship with available nitrogen and a moderate association with phosphorus. Micronutrients were also strongly inter-correlated, suggesting co-variation under similar soil conditions. The study highlights the importance of texture, soil reaction, and organic matter in governing nutrient availability in red cotton-growing soils.