Soil cover of the northern most regions of Eurasia are considered as underestimated in terms of their possible role in expansions of current agriculture to the cryolithozone. In this context, abandoned agricultural soils of Yamal region were investigated in terms of morphology, chemistry and taxonomy microbiome compositions and compared in these terms with mature tundra and taiga soils of pristine environments. The level of soil fertility was low in all cases - former agricultural soils and pristine ones. The level of microorganism's biodiversity was higher in soils of agricultural lands. This fact indicates that the agricultural soil treatment in polar terrestrial ecosystem results in increasing of soil microbial biodiversity due to diversification of ecological niches. Also the is an essential lack of nitrogen sources in all permafrost affected soils studied.