Fertilizantes organominerais como alternativa a adubação convencional na soja

Abstract

In soybean fertilization management, traditionally only mineral fertilizers are used. However, this has been changing with the inclusion of pure organic fertilizers or mixtures with minerals. By combining mineral fertilization with organic matter, it is possible to increase crop growth and productivity in the long term. Mineral fertilizers, although showing positive results in plant production, have a high cost, and for this reason, there is an interest in studying different sources of inputs, aiming at a more efficient and sustainable management of agricultural production, and in this context, organomineral fertilizers show promise. Thus, the objective of this work was to evaluate the efficiency of organomineral fertilizers replacing conventional soybean fertilization. The experiment was installed in the field, in the 2023/2024 growing season, in the experimental area of Chapadão do Sul, MS. The experimental design used was a randomized block design with ten treatments and four replications. The treatments consisted of the use of pure mineral fertilizer or its mixture with organic compounds, in different proportions: control; mineral 50% (M50); 70% (M70) and 100% (M100); supergan 50% (S50); 70% (S70) and 100% (S100); supergan plus 50% (SP50), 70% (SP70) and 100% (SP100). For the mineral fertilizer, the 11-52-00 formulation was used, at doses of 45, 63 and 90 kg ha-1 of P2O5, respectively for 50, 70 and 100% of the doses. For the organomineral fertilizer, the 06-22-01 formulation was used, which provides the same 45, 63, and 90 kg ha-1 of P2O5, respectively for 50, 70, and 100% of the doses. The organomineral fertilizers (Supergan and Supergan Plus) are formulated with mineral fertilizer enriched with manure based on chicken litter and 10 additional bacteria. The total plant height, leaf chlorophyll content, grain weight per plant, thousand-grain weight, and grain yield were evaluated. For plant height, all treatments, except M50 and S50, exceeded the control, promoting average gains of 16% for this variable. The highest chlorophyll value was obtained with the SP70 treatment, promoting gains of 26.5% and 14.5% when compared to the control and the use of mineral fertilizers, respectively. The grain weight per plant obtained with the organic fertilization S70 and SP70 was 16.3% higher than the fertilization of plants with mineral fertilizers, while the thousand-grain weight obtained in the organomineral treatment SP70 exceeded by 9.8% the result achieved with mineral fertilization. The use of organomineral fertilizer increased soybean grain yield in all treatments, except S50 and S100, when compared to mineral fertilization alone. The highest values were obtained with the SP70 treatment, which surpassed the control by 45.1% and mineral fertilizers by 17.3%, resulting in an increase of 12.9 sacks per hectare. It was concluded that the use of organomineral fertilizers promotes an increase in chlorophyll content, components of soybean production and grain productivity, compared to the use of mineral fertilizers alone.