Soil organic carbon recovery and coffee bean yield following bauxite mining

Abstract

AbstractBauxite mining requires the removal of the vegetation and topsoil, thus causing considerable impacts on both natural and managed ecosystems. This is typically the case of agricultural activities across Minas Gerais, South‐eastern Brazil, where bauxite mining often displaces pastures and coffee plantations. In this study, our objective was to assess the effects of chemical and organic fertilizations combined with cover crops on the re‐establishment of coffee plantations following bauxite mining. The experiment consisted of a split‐plot design which main plot received 4 types of fertilization: no fertilization, chemical fertilization (CF), poultry litter (PL), and CF + PL. In subplots, 4 cover crops were cultivated in between the rows of the coffee plantation, including: no cover crops, grass (Brachiaria brizantha [B]), legume (Stylosanthes spp. [S]), and B + S. We had 4 blocks as replicates. Organic and chemical fertilization (PL + CF) combined with cover crops (B + S) led to significant recovery of soil organic carbon (SOC), soil organic nitrogen (SON), and KMnO4‐oxidizable SOC. PL + CF and B + S also led to SOC increments of 14.5 g kg−1 soil (0–10‐cm depth). Based on isotopic data (13C), both cover crops, isolated or combined, contributed to the recovery of SOC. Over 3 consecutive harvests, coffee bean yield was consistently above 1,800 kg ha−1 under PL or PL + CF, except when B was the only cover crop. Managing fertilization and cover crops can determine the recovery of SOC, SON and the capacity of soil to sustain the re‐establishment of coffee plantations following bauxite mining.