Increasing livestock grazing intensity reduces soil organic carbon and infiltration capacity in Miombo woodlands of Tanzania.

The intensity of livestock grazing has been increasing in Miombo woodlands as a result of rising livestock numbers and limited grazing resources in alternative vegetation types. This study investigated the effect of light, medium, and high grazing intensities (GI) on soil organic carbon (SOC) and field-saturated soil hydraulic conductivity (Kfs) across nine Miombo woodlands spanning three districts in Tanzania with diverse climates and landforms. We hypothesize that high grazing intensities will negatively affect SOC and soil infiltration capacity. Grazing intensities were classified using two methods; stocking rate method based on official livestock population records and scoring method based on field observations. Data for this study was collected from nine Miombo woodlands found in villages performing livestock grazing in Miombo woodlands of Tanzania. We collected 188 soil samples for SOC and Bulk Density (BD) determination and 117 sample plots for soil infiltration measurements. Our results indicate that medium and high grazing intensities substantially reduced SOC content and Kfs compared to light grazing intensity. These findings suggest that Miombo woodland soil is degraded under medium and high grazing intensities. Efforts should be directed towards promoting management practices that reduce the number and frequency of livestock grazing in Miombo woodlands for biodiversity and water conservation.