Influence of Sewage Sludge and Farmyard Manure Conjugated with RDF (NPK) on Yield and Economics of Green Gram (Vigna radiata L.) under Zaid Conditions

Abstract

A field investigation was conducted during the Zaid seasons of 2023 and 2024 at the Research Farm of the Department of Soil Science and Agricultural Chemistry, Sam Higginbottom University of Agriculture, Technology and Sciences (SHUATS), Prayagraj, Uttar Pradesh, India, to evaluate the effect of sewage sludge and farmyard manure (FYM) integrated with the recommended dose of fertilisers (RDF) on the yield and economics of green gram (Vigna radiata L.). The experiment was laid out in a factorial randomised block design (FRBD) with sixteen treatment combinations consisting of four levels of sewage sludge (0, 35, 70, and 105%) and four levels of FYM (0, 35, 70, and 105%) along with RDF. Each treatment was replicated three times. The experimental soil was sandy loam in texture with a pH of 6.89, low organic carbon (0.37%), low available nitrogen (238.31 kg ha-1), medium available phosphorus (21.41 kg ha-1), and medium available potassium (141.40 kg ha-1). The green gram variety ‘Star-444’ was sown. The results revealed that integrated nutrient management significantly enhanced seed yield, straw yield, and economic returns over RDF alone. Among all treatments, the application of 105% sewage sludge + 105% FYM + RDF (T16) produced the highest pooled seed yield (1356 kg ha-1), straw yield (2561 kg ha-1), gross return (₹123,709 ha-1), net return (₹70,455 ha-1), and benefit–cost ratio (2.32). The study demonstrated that the combined application of sewage sludge and FYM with RDF considerably improved crop productivity and profitability through enhanced nutrient availability, improved soil physical conditions, and sustained nutrient release.