EN
In order to show the influence of soil pH and soil suitability complex on potato yield, long term experiments were carried out at different N doses (40 - 160 kg N ha⁻¹) and under different soil and climatic conditions (40 - 160 kg N ha⁻¹) in 1971 - 1990. Experiment results for each of the four soil suitability complexes were classified according to soil pH into following groups: pH in KCl 4.5; 4.6 - 5.5, 4.6 - 6.5 and 6.5. The optimum soil pH for potato production was found to dependent on the soil suitability complex.