Legume intercropping and phosphorus management enhance the productivity and profitability of winter maize in calcareous soil

Winter maize exhibits an extended growth duration. Due to this longer growth period, it requires greater nutrient inputs, particularly phosphorus (P). However, in calcareous soils, a substantial portion of applied P becomes fixed due to reactions with calcium and magnesium, forming insoluble calcium-phosphate complexes. Additionally, the low soil temperature during the winter season further decreases phosphorus mobility and diffusion in the rhizosphere, thereby reducing its availability for plant uptake. Winter maize is sown in October–November and shows limited growth until mid-February, offering a suitable window for intercropping. The field experiment was conducted at Dr. Rajendra Prasad Central Agricultural (RPCAU), Pusa, Bihar during the rabi season of 2024 and 2025, comprising 2 factors that were laid out in split plot design (SPD) with 3 intercrop combinations and 5 nutrient management practices in 3 replications. The maize variety chosen for the study, DKC 9081. Among the intercropping treatments, winter maize + vegetable pea was the most effective, showing superiority over all other treatments in terms maize equivalent yield (10.69 and 11.82 t ha-1) along with the maximum net return (₹187430 and 228423 ha-1) and the highest benefit-cost ratio (2.13 and 2.58), the other intercropping treatments. Under nutrient management, 100 % recommended dose of phosphorous (RDP) + nano di-ammonium phosphate (nano-DAP) (10.43 and 11.10 t ha-1) recorded about 45 % and 43 % yields than the control (7.18 and 7.77 t ha-1) in both year of experimentation. Winter maize + vegetable pea with 100 % RDP and nano-DAP achieved the highest yield and profitability, outperforming legume intercropping systems.