Soil organic carbon (SOC) is the major component of the terrestrial carbon (C) budget, a key indicator of environmental sustainability. So, estimating SOC stock and soil carbon (C) sequestration dynamics is important for evidence-based and carbon-conscious decisions. Quantification of SOC stock and soil C sequestration affected by land-use changes (LUCs) have received much attention in addressing food and climate security. This study aims to estimate the dynamics of SOC stock, soil C sequestration and associated soil parameters affected by major LUCs from 2012 to 2021 in Awi highlands of Amhara Regional State of Ethiopia. The study area has experienced dramatic LUC, particularly plantation and growing of Acacia decurrens (J.C. Wendl.) tree followed by recurrent deforestation and then cropping and back to the plantation. The study quantified spatial and temporal dynamics of SOC stock, soil C sequestration and associated changes affected by the LUCs. A total of 22 topsoil (0–20 cm) legacy data was obtained from the Ethiopian Soil Information System (EthiSIS) database of 2012. The same number of samples were collected at the same locations in 2021 by using the same sampling procedure as that of 2012. In addition, the same number of core samples were collected in 2021 for bulk density analysis. To estimate the unmeasured bulk density of legacy data, we applied a pedotransfer function. We used empirical equations and basic statistics to assess changes in SOC stock and C sequestration rate between the two periods. Statistically significant variation (P < 0.01) in SOC stock and C sequestration was observed between the two periods. LUC from acacia plantation to croplands caused a decline of SOC stock by −30.16%, and it also caused the decline of total nitrogen stock, available phosphorus, cation exchange capacity (CEC). However, the reverse LUC caused an increase in SOC by 27.74% and the abovementioned soil parameters. LUC from plantation forest to cropland caused emission of 8.3 tons of CO₂ year⁻¹. Generally, overall LUCs caused the net negative change in SOC stock by (−2.42 %) and associated soil parameters in the last ten years. Our study provides evidence that overall LUCs in the current study site caused a decline in SOC stock, along with associated soil parameters with carbon emitted to the atmosphere. Hence, sustainable land-use management options which can offset losses in SOC stock should be implemented soon.

土壤有机碳 (SOC) 是陆地碳 (C) 预算的主要组成部分，是环境可持续性的关键指标。因此，估算 SOC 储量和土壤碳 (C) 固存动态对于循证和碳意识决策非常重要。受土地利用变化 (LUC) 影响的 SOC 储量和土壤碳固存的量化在解决粮食和气候安全方面受到了很多关注。本研究旨在估计 2012 年至 2021 年埃塞俄比亚阿姆哈拉州阿维高地的 SOC 储量动态、土壤 C 固存和受主要 LUC 影响的相关土壤参数。研究区经历了巨大的 LUC，尤其是金合欢的种植和种植(JC Wendl.) 树，随后反复砍伐森林，然后种植并返回种植园。该研究量化了 SOC 储量、土壤 C 固存和受 LUC 影响的相关变化的时空动态。从 2012 年埃塞俄比亚土壤信息系统 (EthiSIS) 数据库中获得了总共 22 个表层土壤 (0-20 cm) 遗留数据。 2021 年使用与2012 年。此外，在 2021 年收集了相同数量的岩心样本用于体积密度分析。为了估计遗留数据的未测量体积密度，我们应用了 pedotransfer 函数。我们使用经验方程和基本统计​​数据来评估两个时期之间 SOC 储量和 C 封存率的变化。统计学显着差异（P < 0。01) 在两个时期之间观察到 SOC 储量和 C 封存。从金合欢种植到农田的LUC导致SOC储量下降-30.16%，同时也导致总氮储量、有效磷、阳离子交换能力（CEC）下降。然而，反向 LUC 导致 SOC 增加 27.74% 和上述土壤参数。从人工林到农田的 LUC 排放了 8.3 吨 CO₂年^-1。通常，在过去十年中，总体 LUC 导致 SOC 储量的净负变化 (-2.42 %) 和相关的土壤参数。我们的研究提供的证据表明，当前研究地点的总体 LUC 导致 SOC 储量以及相关土壤参数与排放到大气中的碳减少。因此，应尽快实施可抵消 SOC 存量损失的可持续土地利用管理方案。