APORTE DE NUTRIENTES À SOJA EM SUCESSÃO POR DIFERENTES ESTRATÉGIAS DE CULTIVO ANTECIPADO DE GRAMÍNEAS E LEGUMINOSA FORRAGEIRA

Abstract

No-tillage systems have been widely adopted as a conservation strategy aimed at promoting several soil benefits, based on the principles of crop rotation and the intercropping of forage legumes with grasses. These practices contribute to the intensification of agricultural production in a sustainable manner by enhancing soil protection, nutrient cycling, and the performance of succeeding crops. In this context, the objective of this study was to evaluate the macronutrient accumulation of Panicum maximum cv. BRS Tamani and Stylosanthes guianensis cv. BRS Bela, grown in monoculture and intercropping systems over two years, and to assess their effects on the agronomic characteristics and yield of soybean cultivated in succession. The experiment was conducted under field conditions at the Instituto Federal Goiano, Rio Verde Campus, Goiás State, Brazil, using a randomized complete block design with four replications. The treatments consisted of four forage production systems: BRS Tamani grass without nitrogen fertilization, BRS Tamani grass fertilized with 120 kg ha⁻¹ year⁻¹ of nitrogen, BRS Bela stylo, and BRS Tamani grass intercropped with BRS Bela stylo. The results showed that the intercropping system of BRS Tamani grass with BRS Bela stylo provided the greatest accumulation of N, P, K, S, Ca, and Mg from day 0 to day 90, demonstrating high efficiency as a soil cover and greater potential for nutrient recycling within the system, thereby reducing the need for external inputs. Furthermore, all soil cover systems significantly improved soybean yield, with the intercropping system standing out due to its greater biomass production, which consequently increased the number of pods per plant, the number of grains per pod, and the thousand-grain weight.