Pasture Restoration Reduces Runoff and Soil Loss in Karst Landscapes of the Brazilian Cerrado

Water erosion is a major driver of soil degradation in the Brazilian Cerrado, intensified by the conversion of natural vegetation into agricultural land. The excessive runoff and sediment generated in poorly covered karst slopes impact the hydrologic cycle of the biome’s sinkholes and underground rivers. This study evaluated the effectiveness of pasture restoration in reducing runoff and soil loss in three experimental farms situated in a vulnerable karst area of Central Brazil. Runoff and soil loss were monitored during three hydrologic years in plots of degraded pasture (DP), restored pasture (RP), and natural savannah (NS), using unbound Gerlach settings. The experiment was carried out on three farms in the Vermelho river basin, which were treated as blocks. The results indicate that pasture restoration reduced runoff by 50% and soil loss by 55–95% when compared to degraded pasture conditions, below on-site erosion tolerance thresholds. Runoff and soil loss in restored pasture (RP) plots fell between DP and NS, though in some cases, soil loss in RP reached levels that are comparable to the natural savannah. Normalized soil loss was highly correlated with runoff (R2 = 0.94), allowing for the latter to be used as a proxy of the former. The increased groundwater recharge and reduced sediment yield resulting from pasture restoration improve on- and off-site resilience in vulnerable karst landscapes and could be utilized as a sustainable soil conservation policy.