Livestock Intensification and Environmental Sustainability : An Analysis Based on Pasture Management Scenarios in the Brazilian Savanna

Most of the Brazilian beef production is concentrated in the Cerrado, which is predominantly maintained in extensive pastures. This land use class occupies ~50 Mha of the biome, of which approximately 2/3 show signs of degradation. Pasture recovery has become an environmental public policy in Brazil, as it improves land use efficiency and contributes to soil carbon sequestration. However, as intensification leads to higher cattle stocking rates and external inputs (fertilizers, liming, etc.), the impact of improved pastures on greenhouse gas mitigation is still debatable. This study focused on the Cerrado biome and aimed to (i) quantify soil carbon stock changes under different scenarios of management and recovery of degraded pastures. In addition, (ii) the potential for capturing carbon in the soil to mitigate emissions of greenhouse gases (GHG) by the intensification of pastures was evaluated. Before the intensification scenario, the total carbon stock was estimated to be ~1,830 Mt for the pasture area, whose spatial distribution corresponded to edaphoclimatic contrasts and pasture conditions. The highest soil organic carbon stocks were observed in the non-degraded pastures. With the increase in carrying capacity, a potential increase of 1/3 in livestock beef cattle production was estimated, owing to the recovery of degraded areas through intensive management. This increment is sufficient to meet the increase in livestock production, projected at ~12% by the end of the decade, if all pasture areas are recovered. In contrast, the increase in soil C stocks was sufficient to compensate for only 27% and 42% of the GHG emissions in areas with intermediate and severe degradation, respectively. Therefore, for a compromise between economy and environment, other strategies are required to reduce GHG emissions and/or enhance C sinks, such as an increase in tree density on the farm. From this perspective, livestock intensification should be based on the landscape scale for the promotion of C stocks and diversity of ecosystem services