Abstract

Understanding and assessing soil organic carbon stock (SOCS) within the framework of greenhouse gas emissions and land degradation is so crucial in combating climate change and enhancing ecological restoration. The goal of this study was to quantify the current SOCS in major land use types in Kersa sub watershed, eastern Ethiopia. Replicated soil samples from 0 to 20, 20 to 40, and 40 to 60 cm depth were collected from three major land uses types: grazing, cultivated, and fallow lands. Analysis of variance (ANOVA) was used to compare means and Pearson correlation analysis was used to see relationships between selected soil parameters. The results of the study revealed significant difference in soil organic carbon stock under the different land use types (P≤ 0.05). Soil under grazing land use type had significantly higher values of SOCS (42.9 t/ha and 32.9 t/ha) than cultivated land use type (32.6 t/ha and 26.3 t/ha) and fallow land use type (23 t/ha and 12.5 t/ha) in surface and sub surface layers, respectively. Similarly, SOCS decreased with soil depth in all the land use types and showed positive and significant correlation (P≤ 0.05) with clay content while negatively and significantly correlated with bulk density. The results show potential contribution of vegetation cover in land use to enhance soil organic carbon sequestration and environmental protection.

Key words: Land use, organic carbon, soil organic carbon stock, carbon sequestration.