Dominant Bacterial Taxa in Chernozems and Factors Affecting Their Abundance in the Bacterial Community

Families and genera of bacteria that predominate in chernozems of the forest-steppe zone have been identified. Microbiological profiling of samples of plowed and unplowed chernozems is performed, using the 16S rRNA gene sequencing, at different phases of the growing period: in June and August. Changes in the proportion of individual bacterial families, depending on land use and time, are shown. Correlations between the occurrence of bacterial families and chemical parameters of soil have been revealed. The predominant role of nitrates in the formation of the community structure and the important contribution of the organic carbon content, soil moisture, and pH in this process are shown. Despite the revealed differences in the proportions of the studied families, depending on land use and the sampling period, the set of dominant bacterial families in the studied samples remains stable. The first six dominant families comprise about 1/4 of the entire community, and the first 20 ones make up about 40%. The obtained results create prerequisites for further study of the variability of the taxonomic composition of the bacterial community in chernozems under various biotic and agrochemical conditions.