BRIDGING THE NITROGEN-POTASSIUM IMBALANCE: STCR-BASED FERTILIZER PRESCRIPTIONS BOOST MAIZE YIELD AND FARM INCOME IN TELANGANA

Abstract

Imbalanced and indiscriminate fertilizer use remains a major constraint from realising the yield potential of maize (Zea mays L.) in the expanding, non-traditional growing tracts of Telangana, India. The present study evaluated the Soil Test Crop Response (STCR) approach for popularising soil-test-based fertilizer recommendations among maize farmers of Kamareddy district. Pre-sowing soil analysis of six farmers’ fields revealed low available nitrogen (87.8–138.0 kg ha{ ¹), low-to-medium phosphorus (11.6–14.6 kg ha{ ¹) and medium potassium (194–237 kg ha{ ¹) status. Using targeted-yield equations for an economic yield target of 4,500 kg ha{ ¹, field-specific STCR prescriptions (133.4–153.4 kg N, 44.9–49.5 kg P‚ O… , 29.1–36.0 kg K‚ O ha{ ¹) were generated and compared against prevailing farmers’ practice, which applied disproportionately high nitrogen and no potassium. STCR-based nutrition increased mean seed yield by 7.5% (3,773 to 4,057 kg ha{ ¹) while reducing fertilizer cost by about 33%, driven primarily by correction of the nitrogen-potassium imbalance. Consequently, the benefit-cost ratio improved from 1.53 to 1.76, delivering an additional net benefit of approximately Rs 9,000 ha{ ¹ across farmers. These results confirm that field-specific, balanced nutrient management under STCR offers a scientifically sound and economically superior alternative to blanket fertilizer recommendations for maize in Telangana’s semi-arid soils.