Slope gradient is a critical factor influencing the dynamics and spatial distribution of soil organic carbon (SOC). Given the regions vulnerability to soil erosion and land degradation, understanding the effect of slope on SOC dynamics is critical for sustainable land management. This study investigates the influence of slope gradient on SOC concentration in Jira watershed of the Tigray region, Northern Ethiopia. Soil samples were collected from the top 20 cm depth across four LULC types (cropland, grazing land, shrub land and forest land) and three slope gradients (gentle, medium and steep). Soil organic carbon concentration analysis was carried out at Shire soil laboratory using the Walkley-Black oxidation technique. One way ANOVA) was used to assess significant difference between the means of SOC at the three slope gradients. The results revealed that slope gradient significantly influences SOC concentration. Forest land constantly had the highest SOC concentration, followed by shrub land, grazing land and cropland. Likewise, a significant inverse relationship was found between slope gradient and SOC concentration across all land use types, with SOC concentrations decreasing as slope steepness increased. This pattern is attributed to increased erosion on steeper slopes, which removes SOC-rich topsoil, and more favorable conditions for SOC accumulation on gentler slopes. The findings underscore that while land use type is a primary determinant of SOC levels, slope gradient exerts a significant modifying effect. This highlights the necessity of implementing targeted soil conservation practices on steeper slopes to mitigate SOC loss and enhance the region’s carbon sequestration potential.
