Impact of long-term cotton cultivation on soil fertility and nutrient dynamics in Telangana

Cotton is a major cash crop in Telangana, India, contributing significantly to the economy and livelihoods of farmers. However, continuous cotton monocropping has led to nutrient depletion, affecting soil fertility and productivity. This study assessed the temporal variation in available macro and micronutrient content in cotton-cultivated soils across six locations in Telangana between February 2023 and January 2024. Soil samples were analyzed for available nitrogen (N), phosphorus (P), potassium (K), iron (Fe), copper (Cu), manganese (Mn), zinc (Zn), boron (B), and molybdenum (Mo), along with humic and fulvic acid content. The results indicated a significant decline in available nitrogen (198 to 189 kg ha⁻¹), phosphorus (22.1 to 20.6 kg ha⁻¹), and potassium (300 to 291 kg ha⁻¹). Similarly, micronutrients showed a decreasing trend, with iron, copper, manganese, zinc, boron, and molybdenum contents declined across all locations. The reductions in humic and fulvic acid content further highlighted the depletion of soil organic matter. These findings suggest that continuous cotton cropping, combined with minimal organic matter return, accelerates soil nutrient depletion.