Corn Yield Response to Microbial Nitrogen, Irrigation and Seeding Rate Strategies

Optimizing nitrogen (N) management in corn (Zea mays L.) production is critical for enhancing sustainability and profitability, especially given its non-nitrogen-fixing nature and the inefficiency of conventional N fertilization due to losses. This study, conducted in 2023 and 2024 at the Tidewater Agricultural Research and Extension Center (TAREC), evaluated the effectiveness of the microbial nitrogen product Pivot Bio® under irrigated and non-irrigated environments. A split-split plot design with three replications was used to assess four N rates (133, 200, 267, and 333 kg N ha^-1), four seeding rates (59,000, 74,000, 89,000, and 104,000 plants ha^-1), and the presence or absence of Pivot Bio®, which allowed a 45 kg ha^-1 N reduction in the biological treatments. Results revealed significant main effects of irrigation, nitrogen rate, and seeding rate on grain yield (p < 0.05), with the highest yield (12,668 kg ha^-1) observed under irrigated conditions with Pivot Bio® and 333 kg N ha^-1. Notably, the interaction between nitrogen and irrigation, seeding rate and irrigation, and nitrogen and seeding rate significantly influenced yield. Under non-irrigated conditions, yield was consistently lower and less responsive to increased N or plant density. These findings suggest that Pivot Bio® has potential as a sustainable nitrogen supplement in irrigated systems, allowing for reduced N application without sacrificing yield