[Change in the microbiol complexes of soddy podzol soil under the influence of long-term spring wheat monoculture]

The special composition and the properties of microorganisms predominant in the soil and in the rhizosphere of summer wheat were studied in the conditions of monoculture and corp rotation. Noticeable differences were found in the composition of microbial complexes: microorganisms belonging to the genus Arthrobacter prevailed in the conditions of corp rotation, whereas cultures of the genera Pseudomonas and Bacillus predominated in the conditions of monoculture. Many of the latter possessed weak catalase activity and drastically decreased the oxidation-reduction potential of the medium. Microbiol complexes in soddy-podzolic soil, when summer wheat was grown as a monoculture for a long period of time, were characterized by the following properties: most species were incapable of utilizing mineral nitrogen; the activity of proteolytic enzymes was low; the denitrifying activity was high.