Responses of microbial communities in different soil types under various management regimes in the Southeast region of Moldavia, Romania

Abstract

In this study, we examined the diversity and abundance of microbial population isolated from different soil types under different agricultural regimes (permanent grassland and arable land under agricultural rotation) from southeast region of Moldavia, Romania. Soil types, human activities and various land management regimes all have great impact on soil biology, but our knowledge of biodiversity of soil microorganisms is still very limited. Therefore, in 2018 we assessed responses of soil microbial communities to various management regimes, and analyzed six soils showing different land use from distinct localities. At each site, five replicate bulk samples were taken, consisting of 10 randomly collected sub-samples from the surface soil (10-15 cm horizon). The samples were transported to the laboratory, stored overnight at 4°C, air-dried at room temperature and sieved (2-mm mesh) prior to further use in the experiment. The influence of soil types, human activities and land use on the total number of microorganisms (CFU*g-1 ), relationships between the main groups (bacteria and fungi) and the spectrum of filamentous fungi from our experiment were established. Occurrence and distribution of filamentous fungi isolated from these soils provide new insights into ecology and niche specialization of several soil-borne species. Overall, genera composition of filamentous fungi from different soil types was not very heterogeneous and many fungal genera were common to all location. Our results suggest that land usage and soil management system have a significant impact on microbial richness and diversity. Extensive use of xenobiotic compounds in agriculture will degrade soil microbial communities, because they affect directly microbial abundance and composition, and indirectly soil texture and fertility