The paper presents the results of the research on the effect of PRP SOL fertilization on the basic chemical properties of soil and composition of soil solution. The soil has been sampled from the level of humus of many years' experiment established on light soil using traditional fertilization (NPK) and PRP SOL fertilizer was used instead of PK fertilization. Nitrogen doses remained the same in both combinations. Collected samples for testing were taken from a depth of 0-20 cm using an automatic soil sampler. In the plots where PRP SOL fertilization was applied, a statistically significant decrease in the content of available forms of potassium and an increase in the amount of available magnesium forms were observed. There was no significant influence of factors used in the experiment on total organic carbon and nitrogen content. Long-term application of PRP SOL fertilization resulted in statistically significant differences in chemical composition of soil solutions. A significant decrease in the concentration of the following components was observed in these plots: K⁺, Na⁺, PO4^3-, NH4⁺ and the increase in pH value. Modification effect on soil solution chemistry was also caused by the species of cultivated plants.