The article assesses the suitability of effective microorganisms (EM) for the reclamation of degraded soils. The aim of the research was to determine the reclamation effectiveness of the use of EM against the background of mineral wool used together with sewage sludge or mineral fertilization with nitrogen, phosphorus, potassium (NPK) on soils degraded as a result of sulfur extraction. The effectiveness of reclamation was assessed on the basis of changes in the total organic carbon (TOC) content and the properties of humic compounds. The obtained results showed that the use of effective microorganisms in relation to mineral wool and wool used in combination with sewage sludge or NPK causes significant changes in the content and quality of soil organic matter. The observed decrease in the content of TOC, humins and an increase in the share of carbon of labile fractions and free and loosely bound with silicate-free (R2O3) and calcium (Ca) humus forms indicate, that in the soils in which effective microorganisms were used, mineralization processes dominated in the transformation of soil organic matter. The humification process resulted in more durable humic compounds with a higher content of humic acids and humic acids to fulvic acids ratio (C-HA:C-FA). Supplementing commonly used materials in soil reclamation with the introduction of effective microorganisms is a promising technology. Further research is necessary to determine the composition of these biofertilisers and the optimal doses at which they should be used.