Background There is scarcity of scientific information on stocks and retention rate of soil organic carbon (SOC) among mixed farming systems in humid Western Ethiopia. The objectives of study were to determine the SOC stocks and retention rates along a 53-km long toposequence of Didessa watershed. The study was conducted in mixed farming systems (annual arable cropping, grazing, fallow, grassland, coffee agroforestry, eucalyptus agroforestry and mechanized irrigated sugarcane production) within an elevation range of 1273 to 2543 m above sea level. Results The results revealed that land use types greatly affected SOC stocks and retention rates in the upper 20 cm soil depth. The SOC stocks ranged from 9.27 to 13.5 Mg C ha −1 (0–20 cm) while the retention rates were 0.11, 0.20, 0.28, 0.31 and 1.14 Mg C ha −1 year −1 for coffee agroforestry, fallow, grazing, eucalyptus agroforestry and irrigated sugarcane production systems, respectively. Conclusion The retention rates demonstrated that the different farming systems are potential source of C sinks. The study indicated that the farming systems are efficient in sequestering SOC and their benefits can be further adopted for their economic values, social significance, restoration of degraded land, and sequestration of carbon (C) in humid tropical Western Ethiopia.

中文翻译：

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埃塞俄比亚西部潮湿 Didessa 地层沿线土地利用的土壤有机碳储量和保留率

背景 埃塞俄比亚西部潮湿的混合耕作系统中，缺乏关于土壤有机碳 (SOC) 存量和保留率的科学信息。研究的目的是确定沿着 Didessa 流域 53 公里长的地形序列的 SOC 储量和保留率。该研究在海拔 1273 至 2543 m 的海拔范围内的混合耕作系统（一年一度的耕作、放牧、休耕、草地、咖啡农林业、桉树农林业和机械化灌溉甘蔗生产）中进行。结果 结果表明，土地利用类型极大地影响了上部 20 cm 土壤深度的 SOC 储量和保留率。SOC 储量范围为 9.27 至 13.5 Mg C ha -1（0-20 cm），而咖啡农林业、休耕、放牧、桉树农林业和灌溉甘蔗生产系统。结论 保留率表明不同的耕作系统是碳汇的潜在来源。该研究表明，农业系统在封存 SOC 方面是有效的，其经济价值、社会意义、退化土地的恢复以及埃塞俄比亚西部潮湿热带地区的碳 (C) 封存可以进一步利用其效益。