Soil acidification in agroecosystems is a natural process that could be accelerated, mainly bythe inappropriate application of mineral fertilizers, or prevented, by sustainable managementpractices. On the basis of a three-year field study in a grassland agroecosystem, the impact ofdifferent rates of fertilization with nitrogen (N), phosphorus (P), and potassium (K) on soil chemicalparameters related to soil acidity was evaluated. It was found that high-rate fertilization withammonium nitrate accelerated the soil acidification process, which was additionally intensifiedby the application of superphosphate and potassium salt. The sum of exchangeable base cations,the values of base saturation and hydrolytic acidity in the soil reflected the interactions between theapplied NPK-fertilizer levels. Considering chemical parameters related to soil acidity studied in thisexperiment, it seems that the best strategies for mitigating soil acidification in grasslands are reducingnitrate leaching, changing fertilizer types and increasing the input of base cations.