Modeling of the Accumulated Nitrogen Loss by Volatilization in Topdressing Fertilization in Corn Plants.

Corn cultivation is one of the most important in the world. Urea possesses a high concentration of nitrogen, which is very important to corn crops, is easily handled, and has a lower cost per kilogram of nitrogen, but it presents high losses of this nutrient through volatilization. Therefore, technologies are developed to minimize these losses, the most widespread being N-butyl thiophosphoric triamide (NBPT). This study aims to select the most appropriate nonlinear model to describe the accumulated loss of nitrogen by volatilization of urea fertilizers of increased efficiency with NBPT applied as topdressing fertilization in corn plants. Urea treated with NBPT not only reduced, but also retarded the accumulated loss of nitrogen by NH3 volatilization. The von Bertalanffy model best adjusted the data for conventional urea fertilizers, while the Gompertz model best adjusted the data for other fertilizers. The UGRAN fertilizer showed the highest accumulated loss with an estimate of 36.503 kg ha-1, registering a loss of approximately 11 kg ha-1 of N on the first day after application, while the UNBPT4 fertilizer recorded the lowest accumulated loss with an estimate of 14.623 kg ha-1, which corresponds to a reduction of 59.9% in relation to the conventional urea.