Impact of real-time nitrogen management on the performance of maize–cowpea intercropping system

Maize has broad adaptability across diverse agroclimatic conditions and plays a vital role in addressing global food and feed demands. As it is a widely spaced crop with slow early growth, intercropping maize with legumes like cowpea can enhance land and resource use efficiency. Additionally, as maize is a heavy nutrient feeder, particularly nitrogen (N), precise nutrient management is essential. A field experiment was conducted during the Rabi season of 2023–2024 at the Post Graduate Research Farm, Centurion University of Technology and Management, Odisha, India, under split-plot design. The study evaluated three maize-based cropping systems (sole maize, maize + cowpea at 2:2 and 2:3 paired rows) with four nitrogen strategies: recommended dose, SPAD (45), NDVI (0.8), and LCC (4). The maize hybrid 'Bayer DKC 9217' was chosen along with the cowpea variety 'KBC 9' with maize blanket recommendation of 120:60:60 kg/ha of N, P₂O₅, and K₂O. Results showed that sole maize recorded the highest growth, yield attributes and yield, closely followed by maize + cowpea (2:2) intercropping. Among nitrogen management practices, the GreenSeeker-based N application produced the highest growth parameters and yield, which was statistically comparable to SPAD-based N management. However, for economic returns, maize paired row + cowpea (2:2) with the GreenSeeker-based nitrogen management recorded the highest gross and net returns of the intercropping system. In terms of overall output, the findings suggest that sole maize with the GreenSeeker-based N management maximises maize yield, however, maize + cowpea (2:2) intercropping combined with Green Seeker-based N application offers a more sustainable and economically viable option for maize cultivation under south Odisha conditions.