Biomass of soil microorganisms in arable chernozem of Moldova

With the use of rehydration method the author investigated the annual dynamics of microbial biomass supply in weakly humus chernozem on the grounds of perennial soil station under monocultures, and also in crop rotation of cereal and cultivated crops on different backgrounds of organic and mineral fertilizers on experiment variants. In connection with cultivating culture, a mode of tillage and a dose of fertilizers the content of microbial mass was varied in the range of 0.202-1.06 mg C/h, that represents 1.34-2.53 % from total soil carbon. It was shown, that arable soils are more poor on content of microbial biomass as compared with virgin lands. The micromycetes, taking an active part in transformation of soil substances, on studied areas were presented by seven genera: Penicillium, Trichoderma, Alternaria, Fusarium, Mucor, Aspergillus and Botrytis with reliable domination of Penicillium genus. These results support this fact, that microorganism environment during practical using of soils acquires a carbooligotrophic properties, which limit the production of microbial biomass and thereby decrease of soil productivity.