Influência da adubação orgânica na produção de grãos na cultura do milho no município de Goiás-GO

Abstract

Poultry and cattle excrement are an excellent source of nutrients, especially nitrogen (N), and, when managed properly, have the potential to partially or fully replace chemical fertilizers in grain production. This study aimed to evaluate the effects of organic fertilizers (cattle manure and poultry litter) compared to mineral fertilizers on corn production in the region of Cidade de Goiás - GO. The experiment was conducted at the Federal Institute of Education, Science and Technology of Goiás, Cidade de Goiás Campus between September 2023 and April 2024. The experimental design was in randomized blocks (DBC), involving 4 treatments and 5 replications, totaling 20 plots of 6 m² (120 m²). The treatments were: control (without fertilization), cattle manure (30 tons/ha) and chicken litter (40 tons/ha), applied as top dressing, and chemical fertilizer NPK 00-21-00 and 20-00-20, 476.7 kg/ha and 220 kg/ha, respectively. For the fertilizer treatment, 515 kg/ha of 20-00-20 was applied as top dressing, 20 days after plant emergence (DAE). Phytotechnical evaluations included measuring plant height and stem diameter at 20, 40 and 60 DAE, and ear insertion height at 120 DAE. Productivity was determined using the Corn Yield Calculator methodology, considering the row and grain count on the ears, followed by drying and correction of grain weight to 13% moisture. The results of this study demonstrate that the fertilizers used had a significant impact on the growth of corn plants, with emphasis on chicken manure, which proved to be the most effective in promoting vegetative development, especially in terms of height and diameter of the stalks at 60 DAE. In terms of productivity, all fertilizer treatments were superior to the control, however no statistical difference was observed between chicken manure, cattle manure and chemical fertilizer, which demonstrates that organic fertilization has the capacity to replace mineral fertilization in grain production.