Refining Fertilizer Requirements for Irrigated Redgram in Alfisols under Changing Moisture Regimes

India is the largest producer and consumer of red gram in the world. It plays a vital role in nutritional security as a major source of dietary protein. A field experiment was conducted during Kharif 2023 and Kharif 2024 at the Regional Agricultural Research Station, Palem, Nagarkurnool District, Telangana State, India, to evaluate the effect of irrigation and nutrient management on growth, yield, economics and soil properties of redgram (Cajanus cajan L.) grown in Alfisols. The experiment consisted of two irrigation levels (rainfed and irrigated) and four fertiliser treatments, including farmers’ practice, RDF, RDF + 5 t FYM ha⁻¹, and 125% RDF + FYM. The pooled results over two years revealed that irrigation significantly increased plant height (168 cm), number of pods per plant (293), and seed yield (2089 kg ha⁻¹) compared to rainfed conditions (1578 kg ha⁻¹). Among fertiliser treatments, application of 125% RDF + 5 t FYM ha⁻¹ recorded the highest number of branches (14.1), pods per plant (313) and seed yield (2093 kg ha⁻¹), followed by RDF + FYM. Economic analysis indicated that irrigation resulted in higher gross returns (Rs. 142,030 ha⁻¹), net returns (Rs. 91,720 ha⁻¹), and benefit-cost ratio (2.8). Among nutrient treatments, the highest net returns (Rs. 78,155 ha⁻¹) and B: C ratio (2.5) were recorded with 125% RDF + FYM. The study concludes that irrigation combined with integrated nutrient management, particularly higher fertiliser dose along with FYM, enhances productivity, profitability, and sustains soil health of redgram grown in Alfisols.