Modeling long-term attainable soil organic carbon sequestration across the highlands of Ethiopia
Modeling long-term attainable soil organic carbon sequestration across the highlands of Ethiopia
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DOI：
10.1007/s10668-021-01653-0
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发表时间：
2021-07
期刊：
影响因子：
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通讯作者：
A. Abegaz;Ashenafi Ali;L. Tamene;W. Abera;Jo U. Smith
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文献类型：
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作者：
A. Abegaz;Ashenafi Ali;L. Tamene;W. Abera;Jo U. Smith
这项跨越埃塞俄比亚高地的研究的目标是：(i) 描述土壤有机碳 (SOC) 储量与生物物理变量之间的关联；(ii) 对与五种改进的土地管理实践相关的可实现的 SOC 封存进行建模和绘制。使用由八个生物物理预测因子驱动的多元线性回归模型研究了 SOC 储量的空间分布。然后，使用广泛使用的 SOC 模型 (RothC) 来模拟未来 20-50 年改善土地管理的 SOC 变化。模拟是由 ISRIC 土壤数据库中 250 m 分辨率的 SOC 储量、pH 值和粘土含量以及来自“增强国家气候服务倡议”数据库的气候数据驱动的。该模型的有机碳输入是根据农业和畜牧资源部和中央统计局的“改良作物品种产量登记册”估算的。经过50年80%有效厩肥施入耕地的保护性耕作后，土壤有机碳总储量增加了169,182,174吨，比仅施入50%有效厩肥时的储量增加量高出2.8倍。引进改良牧草品种和控制水土流失的措施是草原净固碳的重要来源。退化景观的造林和再造林以及自然生态系统的保护进一步增加了土壤碳。这凸显了改进土地管理实践对有机碳固存的重要性，这反过来又可以提高农业生产力、粮食安全和可持续发展。
The objectives of this study across the highlands of Ethiopia were: (i) to characterize the association between soil organic carbon (SOC) stocks and biophysical variables and (ii) to model and map attainable SOC sequestration associated with five improved land management practices. The spatial distribution of the SOC stock was studied using a multiple linear regression model driven by eight biophysical predictors. A widely used SOC model (RothC) was then used to model changes in SOC over the next 20–50 years of improved land management. Simulations were driven by the derived SOC stocks, pH and clay contents that are available in the ISRIC soils database at 250 m resolution and climate data from the “Enhancing National Climate Services Initiative” database. Organic carbon inputs to the model were estimated from the “Improved Crop Varieties Yield Register” of the Ministry of Agriculture and Livestock Resource and the Central Statistics Authority. After 50 years of conservation tillage with 80% of available manure applied to cultivated land, the total SOC stock increased by 169,182,174 t, which is 2.8 times higher than the stock increase with only 50% of available manure applied. Introduction of improved pasture species and measures to control soil erosion was an important source of net carbon sequestration in grasslands. Afforestation and reforestation of degraded landscapes and protection of natural ecosystems further increased soil carbon. This highlights the importance of improved land management practices to SOC sequestration, which in turn could enhance agricultural productivity, food security and sustainable development.