Sewage sludge, thanks to its content of nutrients, can be used as a fertilizer for lawns. The aim of this study was to determine the relationship between the applied dose of sewage sludge and variety of lawn grasses and changes in the quality and quantity of microorganisms in the root zone of grass.The community of fungi isolated from the rhizoplane was significantly dominated by fungi belonging to the Fusarium genus, including F. oxysporum. The share of these fungi in the isolated community increased with the dose of sewage sludge. It was also found that the share of some saprotrophic fungi significantly increased after application of the sludge at a dose of 60 t•ha^-1 and decreased after its application at the highest dose of 150 t•ha^-1. The lowest number of fungi of the Fusarium genus was observed in the roots of perennial rye-grass (30.3% of all isolates), while their highest number occurred in creeping red fescue (44.3% of all isolates). Based on all the results, such as the level of dominance, the number of potential pathogens and bacteria and fungi saprotrophic observed that the dose of 60 t•ha^-1 is the most favorable option, while the use of a dose of 150 t•ha^-1 may increase the share of pathogenic fungi in the community fungi, without causing beneficial changes in the number of microorganisms inhabiting rhizosferę terms lawns where no fertilizer was applied.