The naturally circumneutral soils of Edirne Province, Turkey, are acidify with increasing use of ammonium sulfate fertilizers. Soil pH governs both the availability of nutrients and the solubility of Al which becomes toxic to plants when exceeding 1 ppm. The average pH of the soils under wheat/ sunflower rotation was 5.11 while average Al, Ca and Mg concentrations were 3.34, 1094.01 and 174.28 ppm, respectively. For over half of the fields, average alumi-num contents of the soils exceeded 1 ppm, the toxicity threshold for plants. Al concentrations were negatively cor-related with pH (r2 =-0.402, p<0.0003). Ca, and Mg concentrations were positively correlated with pH values (r2 =0.320, p<0.0008; r2 =0.213, p<0.008, respectively). Ca and Mg, were correlated to Al as a power law with an expo-nent of 0.25 (r2 =0.293, p<0.001; r2 =0.557, p<0.0001, respectively).