Humid climate, short growing season and negative average annual temperature are the determining factors in the development of ecological-trophic groups of soil microorganisms. For analysis, the study examined alluvial soils of the river. Deep Sabun. The study found that automorphic soils have weak soil nitrogen cycle processes carried out by soil microscopic fungi. Alluvial soils are more active in the microbiological aspect and have a higher biological diversity of microorganism species and soil processes.