In northwestern Ethiopia, a conventional teff (Eragrostis tef (Zucc.) Trotter) monoculture was converted into a rotational agroforestry system (teff-Acacia agroforestry), which consists of the sequence i) teff-Acacia decurrens intercropping (1^st year), ii) grass-A. decurrens silvopasture (2^nd year), iii) A. decurrens plantation (3^rd–4^th year), and iv) on-site charcoal production from A. decurrens (end of 4^th year). This study is the first one to comprehensively show how the agroforestry system affects soil organic carbon (SOC) and soil nutrients. Soil samples were collected from the teff-Acacia agroforestry and conventional teff fields at two different sites (site I and II) and they were used to determine soil pH, black carbon, SOC, soil total nitrogen (STN), extractable phosphorus (P), potassium (K), magnesium (Mg), sodium (Na), and calcium (Ca) contents. At site I (0–10 cm soil depth), charcoal production spots in teff-Acacia agroforestry had higher soil pH (20%), black carbon (164%), SOC (48%), P (687%), and K (788%) contents compared to outside charcoal production spots. Soil organic carbon and STN contents in the 1^st and 2^nd teff-Acacia agroforestry rotations were significantly higher (SOC: 112–169%, STN: 100–131%) than teff fields. At site II, SOC stocks (0–100 cm) in the 1^st agroforestry rotation were not significantly different from teff fields. However, they were 159% and 244% greater in the 2^nd and 3^rd agroforestry rotations, respectively, compared to teff fields. Conversion of teff fields to teff-Acacia agroforestry for a 12-year period increased SOC stocks by 21 Mg C ha^–1 per year. Our results demonstrated that locally adopted agroforestry practices can increase SOC and nutrients in the long term, thereby contributing to enhanced soil fertility and improved climate change mitigation strategies via carbon sequestration.

在埃塞俄比亚西北部，传统的画眉草 ( Eragrostis tef (Zucc.) Trotter) 单一栽培被转化为轮作农林业系统 (teff-Acacia agroforestry)，该系统由序列 i) teff- ^Acacia decurrens间作（第 1年）、ii ) 草- A. decurrens ^silvopasture（第 2年），iii) A. decurrens种植园（第 3^至第4年），以及 iv) A. decurrens的现场木炭生产（第 4^年末）。这项研究是第一个全面展示农林业系统如何影响土壤有机碳 (SOC) 和土壤养分的研究。从两个不同地点（地点 I 和 II）的 teff-Acacia 农林业和常规 teff 田地收集土壤样品，用于测定土壤 pH 值、黑碳、SOC、土壤总氮 (STN)、可提取磷 (P) 、钾 (K)、镁 (Mg)、钠 (Na) 和钙 (Ca) 含量。在站点 I（0-10 cm 土壤深度），teff-Acacia 农林业的木炭生产点具有较高的土壤 pH 值（20%）、黑碳（164%）、SOC（48%）、P（687%）和 K (788%) 含量与外部木炭生产点相比。1 、2^日土壤有机碳和STN^含量teff-Acacia 农林业轮作显着高于 teff 田地（SOC：112-169%，STN：100-131%）。在站点 II，^第一次农林业轮作中的 SOC 储量（0-100 厘米）与苔麸田没有显着差异。然而，与苔麸田相比，它们在第 2 次和第 3 次农林业轮作中分别高出¹⁵⁹ %^和244% 。在为期 12 年的时间里，将 teff 田地转变为 teff-Acacia 农林业使 SOC 储量每年增加 21 Mg C ha ^-1。我们的研究结果表明，当地采用的农林业实践可以长期增加 SOC 和养分，从而有助于提高土壤肥力并通过固碳改善气候变化缓解策略。