Knowledge of the spatial distribution of soil pH (potential hydrogen) is important for soil and crop management practices aimed at improving agricultural productivity. The present study was conducted to investigate the spatial coverage of the various pH classes of Ethiopian soils. Analysis of the harmonized world soil data base (version 1.2) using GIS and remote sensing tools and classification of the top soil pH data revealed 33.56, 23.44 and 43.01 percent of the country’s land area to be of acidic, neutral and alkaline pH range, respectively. Acid soils were dominantly distributed in the western parts of the country while alkaline soils mainly occupied the eastern parts. The regional states and their corresponding zones located in the western or eastern part of the country also shared the same problem. The southern, southeastern and northwestern parts of the country were mainly covered with soils of neutral and slightly acidic pH range. Nearly, one-third (32.87%) of the country’s overall land area was occupied with soils that possess toxic elements of acidic and alkaline pH classes (i.e., Al3+, salts and/or Na+). Thus, soil amendment strategies as well as tolerant/resistant crop species and/or varieties relevant for acid and alkaline soils should be used to improve crop productivity in these areas. The remaining two-third of the country’s land area (66.48%) was covered with soils of pH classes elemental toxicity is not expected and hence could be considered suitable for crop production.

Keywords: Ethiopian soils, soil pH map, soil pH classification, acid soils, alkaline soils