ИСТИНА

The study of soils’ metagenome is promising for the development of both soil microbiology, and for the soil processes trends in soils of anthropogenic origin. The analysis of 16 S rRNA gene amplicon libraries of typical chernozem in conditions of different land use systems revealed that the way of agricultural use is a strong determinant of soil microbiome taxonomic composition. It was shown that the continuous «bare fallowing» (for 50 years) lead to the establishment of olygothrophic components of microbial community, including spore-forming members of phylum Firmicutes. The increase in Acidobacteria lineages abundance may be an indicator of some acidification of soil during long-time fallowing application. The variant of continuous wheat cropping lead to increasing in Proteobacteria lineages. The variant of soil under native steppe vegetation was characterized by the highest values of biodiversity indices - species richness and eveness, which can indicate the occurrence of soil recovering. This variant was also characterized by the maximum content of agricultural valuable aggregate fraction of 2-5 mm size