Our studies utilize enzymatic indicators and microorganism numbers for the estimation of soil environment reaction to the applied differentiation of organic fertilizers and maize (Zea mays L.) cultivation. The experiment had a field character. In different terms connected with the development of maize, the activities of, dehydrogenases and acid phosphatase were determined in the soil. The number of microorganisms (bacteria, actinomyces, fungi, oligotrophic, copiotrophic microorganisms) was determined by the plate method, on adequate agar substrates. Activity levels of the selected enzymes were defined using the spectrometrical method. The obtained results show that applied organic fertilization, as well as the cultivation of soil, had a significant effect on the activity of the analyzed soil enzymes. It was found that dehydrogenases and acid phosphatase activity at the time of the experiment was the highest after the introduction into the soil of sewage sludge (5 tons d.m.·ha^-1·year^-1).