PLANTAS DE COBERTURA DE FORRAGEIRAS TROPICAIS: PRODUÇÃO DE BIOMASSA, CICLAGEM DE NUTRIENTES, ALTERAÇÕES FISIOLÓGICAS E PRODUTIVIDADE DA SOJA

Abstract

The constant discussion about the role of agriculture and livestock in food production and sustainable management of production systems and resources, has driven the search for knowledge of the main physiological effects occurring in crop-livestock integration systems and their effects on soybeans final productivity. Thus, this study aimed to evaluate the impact of different cropping systems after intercropping with corn in the development of soy plants and unveil the physiological changes that alter the CO2 flow from the soil as well as what components explain the soil respiration rates. In addition, to evaluate the control of desiccation efficiency, biomass production, nutrient accumulation, and soybean productivity in the biomass of forage plants of the genus Panicum maximum after intercropping with corn in the off-season. The experiment was field tested from January 2021 to March 2022 in a randomized block design with four replications. The treatments consisted of the ground cover biomass: monoculture corn, monoculture Tamani guinea grass, monoculture Zuri guinea grass, corn + Tamani guinea grass in the row, corn + Tamani guinea grass in the interrow, corn + Zuri guinea grass in the row, and corn + Zuri guinea grass in the interrow. Plus, an additional soybean treatment with no cover crop biomass. We conclude that cropping systems containing biomass covering the soil improve soybean physiology due to increased photosynthetic rates promoted by higher leaf chlorophyll content. In addition, aboveground biomass and soil organic carbon content increased without a concomitant increase in soil respiration. The results prove that Tamani and Zuri guinea grass, when cultivated as intercrops with corn in the second cropping season, can be used in crop-livestock integration systems, improving the amount of carbon assimilated into the ecosystem, soil health, and maintaining a sustainable production system. The integrated systems with tropical forage for soil cover also proved to be an efficient technique for biomass production and nutrient cycling, by making better use of soil nutrients and contributing to the sustainability of agricultural systems.