Organic carbon stock at different altitudes and soil depths of Hakim Gara shrub land in Harari region of Eastern Ethiopia

Reliable soil organic carbon stock measurements are essential for predicting the soil carbon emission on global warming. Soil samples (0-20 and 20-40 cm depth) were collected from six sites situated at an elevation ranging from 2001 to 2113 m above MSL of Hakim Gara shrub land in Harari region of Eastern Ethiopia, suitable for growing niger (main crop), groundnut, sunflower and safflower. The organic carbon decreased with depth (7.10 to 3.20%) while bulk density increased with depth (1.12 to 1.40g/cm³) at different sites. Total porosity exhibited decreasing trends between 52.13 to 46.17%. Organic carbon was positively correlated with altitude. The data pointed out that stakeholders should focus on the management activities to improve the soil organic carbon and bulk density for higher carbon stock capacity of niger-growing soils in Harari region of Eastern Ethiopia.