Circular and agroecological practices to improve integrated systems

Conventional agriculture encompasses agricultural and livestock systems that are highly specialized and often associated with a negative environmental impact and external input dependency. Integrated systems are a sustainable alternative for production, where, in addition to increased diversity, nutrient recycling is promoted under a circularity approach. This research evaluated the effect of circular and agroecological practices on the yield and soil properties of an integrated corn+sheep+forage system. Four treatments were tested in a completely randomized design with three replications: maize+vetch association without fertilization (MV), maize fertilized with sheep manure (MM), maize+vetch association fertilized with sheep manure (MVM), and maize with chemical fertilization (CFM). The response variables were grain and forage yield (maize stover+vetch), soil bulk density, soil organic matter, and soil nutrient content (nitrogen, phosphorus, and potassium). The results revealed significant statistical differences (P=0.003) in forage yield and soil potassium content. The combination of animal fertilizer and crop association practices (MVM) increased the grain and forage yield compared to the chemically fertilized monoculture (CFM) by 2.3 and 5.8 Mg ha^-1, respectively. In the soil, the MVM treatment increased potassium content (P=0.027), organic matter, and ammoniacal nitrogen and decreased bulk density. In conclusion, implementing circular and agroecological practices allows for a sustainable improvement in integrated systems, as production costs for fertilization and animal feed are reduced, crop yield per unit area is increased, soil quality is improved, diversity in the production unit is favored, and the environmental impact is reduced by promoting nutrient recycling.