Estoque de carbono com uso de fertilizantes organominerais associado com o uso de plantas de cobertura no cultivo de soja

Abstract

The use of organomineral fertilizers is an interesting alternative to complement phosphate fertilization, as it releases nutrients gradually and also helps to increase the carbon stock in the soil. This study aimed to evaluate the effect of different cover crop management systems and phosphate fertilizer sources on phosphorus availability, organic carbon stocks, and soybean, at the Federal University of Mato Grosso do Sul (UFMS) School Farm in Chapadão do Sul, Mato Grosso do Sul, Mato Grosso do Sul, Brazil. The experiment was conducted in a split-plot design, with plots consisting of the cover crop management systems Urochloa ruziziensis and Crotalaria spectabilis, grown singly and intercropped with corn; and subplots consisting of fertilizers: two organomineral fertilizers (ORG1 and ORG2) and one mineral fertilizer (single superphosphate). Soil phosphorus fractions, organic carbon stocks, and soybean yield were evaluated. The results indicated that soil phosphorus levels were influenced by side-cropping management, especially in the available and inorganic P fractions. The Corn + Urochloa

ruziziensis intercrop treatment promoted the highest P availability, regardless of the fertilizer type used. In contrast, total phosphorus, occluded P, and organic P did not show significant differences between treatments. Soybean grain yield was higher in the Corn + Urochloa ruziziensis + Crotalaria spectabilis intercrop treatments, as well as in the plots with Urochloa ruziziensis and Crotalaria spectabilis alone, highlighting the potential of these species to improve phosphorus use efficiency and soil fertility.