Effect of Bamboo Plantation and Adjacent Land Uses on Soil Organic Carbon Stock in Sidama Highlands, Ethiopia

Monitoring soil organic carbon (SOC) stocks and related physicochemical properties is fundamental for informed decision‐making in sustainable land management and climate change mitigation. This study investigated the effect of bamboo ( Arundinaria alpina ) plantations and adjacent land uses—natural forest, enset‐based agroforestry, and wheat–barley cropland—on SOC, soil aggregates, bulk density (BD), and moisture content (MC). The study was conducted in the Hula District of the Sidama Region, Southern Ethiopia. A total of 72 composite soil samples were randomly collected from the land uses at three soil depths (0–20, 20–40, and 40–60 cm) and two altitudes (2450–2550 and 2650–2750 m above sea level). The SOC was analyzed by the Walkley and Black method, and soil aggregates by dry sieving. Statistical variations in soil parameters across the land uses were assessed using analysis of variance. Results showed that the overall mean values of SOC, macroaggregates, and MC follow the order: natural forest ≥ bamboo plantation > enset‐based agroforestry > wheat–barley cropland. Meanwhile, it followed the reverse order for BD and microaggregates. The highest overall total SOC stock was measured in natural forest (235.9 Mg ha −1 ) followed by that in bamboo plantation (230.0 Mg ha −1 ) and enset‐based agroforestry (199.7 Mg ha −1 ) while the lowest was measured in wheat–barley cropland (155.6 Mg ha −1 ). This indicates that natural forests and bamboo plantations favored the formation of good soil structures due to the high content of organic matter input, slow decomposition, and less soil disturbance. This finding highlights the C sequestration potential of bamboo plantations by demonstrating their comparability to natural forests and higher value than enset‐based agroforestry. Therefore, it underscores the need for enhanced management practices in highland bamboo plantations to further optimize their role in SOC storage.