EN
The aim of study was to determine the influence of growing fertilizer rates on soil reaction. Soil samples were taken from experimental plots, where different amounts of NPK fertilizers were applied for perennial grasses within 6 years (1986 - 1992). The experimental design was 12 treatments in 4 replications, and established in sod-gleysolic loamy sand. Potential acidification of soil as a result of fertilization was calculated based on CaCO₃ balance and obtained results validated with the analytical tests of topsoil (0 - 20 cm) and subsoil (20 - 40 cm) reaction before and after experiment. Obtained results showed low performance of data obtained by calculation CaCO₃ balance, thereby using only CaCO₃ balance, it is risky to forecast soil acidification. In spite ofthat the used fertilizer rates changed in the widely ranges between treatments (N₀P₀K₀ - N₃₀₀P₁₂₀K₂₄₀), fertilization had not significant influence on soil reaction.