The soil acidity level is a key soil characteristic that determines soil nutrient availability, soil microbial activities, and crop growth. This study was carried out to predict the extent and severity of soil acidity based on 109,704 soil pH samples collected from soil laboratories and compiled from various studies. Rainfall, altitude, slope gradient, soil, and land cover were considered to generate multivariate interpolated soil pH surface. The performance of the co–kriging model was found to be satisfactory with a standard error of 0.77, root mean square error of 0.51, and R² of 0.74. The model estimates showed that 47% of the Country's total area and 45% of the rainfed areas are acidic (pH < 6.5). Out of the total area of the Country, 3.7% (42,264 km²) is found to be extreme to strong acidic (pH < 5.5), 20.7% (236,724 km²) is moderate acidic (5.6 < pH < 6.0), and 22.5% (257,290 km²) is slight acidic (6.0 < pH < 6.5), whereas the respective coverage in the rainfed agricultural areas is found to be 12% (80,732 km²), 18% (120,500 km²), and 14.6% (97,202 km²). As informed by the model results, integrated acid soil management efforts should be given a priority to severe soil acidity areas of western, central, northwestern, and southern parts of the Country. Thus, appropriate integrated land management techniques that enable to reduce soil acidity and halt land degradation should be initiated, informed by the map produced. Regularly updating the extent and distribution of surface and sub-surface soil acidity is recommended in future studies.

中文翻译：

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埃塞俄比亚雨养区表层土壤酸度的范围和分布

土壤酸度水平是决定土壤养分有效性、土壤微生物活动和作物生长的关键土壤特征。本研究基于从土壤实验室收集并从各种研究中收集的 109,704 个土壤 pH 值样本，以预测土壤酸度的程度和严重程度。降雨量、海拔高度、坡度、土壤和土地覆盖被认为是生成多变量插值土壤 pH 表面。发现协同克里金模型的性能令人满意，标准误差为 0.77，均方根误差为 0.51，R ²为 0.74。模型估计表明，该国总面积的 47% 和雨养区的 45% 是酸性的（pH < 6.5）。占全国总面积的 3.7%（42,264 平方公里²) 被发现为极强酸性 (pH < 5.5)，20.7% (236,724 km ² ) 为中酸性 (5.6 < pH < 6.0)，22.5% (257,290 km ² ) 为弱酸性 (6.0 < pH < 6.5) )，而雨养农业区的覆盖率分别为 12% (80,732 km ² )、18% (120,500 km ² ) 和 14.6% (97,202 km ^{2 )}）。根据模型结果，综合酸性土壤管理工作应优先考虑该国西部、中部、西北部和南部的严重土壤酸性地区。因此，应根据所绘制的地图启动适当的综合土地管理技术，以降低土壤酸度并阻止土地退化。建议在未来的研究中定期更新地表和次表层土壤酸度的范围和分布。