Introduction of microorganisms into the soil is a fundamental problem in application of microbial preparations in agriculture, crop production and ecology. Its effectiveness depends on many factors (i.e. the type and strain of microorganism, the physical and chemical properties of the soil, plant cover, climate and so on), which are not well understood, leading to a high variability of the results of application of microbial preparations. In this article, there is reported the first investigation of survival and sporulation dynamics of Bacillus megaterium 501 introduced into sodpodzolic soil, depending on the temperature of the soil, organic matter content and herbicide prometryn, the 2-methylthio-4,6-bis (iso-propylamino)-sim-triazine, application.