At the light-chestnut soils of South Volga there are widely spread the types of genera Реnicillium and Aspergillus, reaching 60% from the whole number of selected myxomycetes. The rest of soil mushrooms is distributed among 18 genera: g. Mortierilla, g. Verticillium, g. Gliocladium and others. The types of genera Реnicillium and Aspergillus reveal antagonism with respect to azotobacter in 50 and 70% correspondingly. Among the other genera of soil there are considerably less number of mushrooms antagonists. Among the types of the genus Aspergillus the most wide spreading there have types Aspergillus niger v. Thegh, A. fumigatus Fres., A. sydowii (Bain. et Sart.) Thom et Church. Almost all types of this genus includes antagonists az. The biggest percent of antagonists was in types A. niger v. Thegh - 100%, A. fumigatus Fres - 50%, A. alliaceus Thom et Church - 60%, A. flavus Lk. - 65%, A. wentii Wehm. - 60%/. The least number of antagonists was revealed at the isolates of the types A. sydowii (Bain. et Sart.) Thom et Church, A. flavipes (Bain. et Sart.) Thom et Church, A. ustus (Bain.) Thom (12%). But it makes itself conspicuous, that the maximal diameter of the zone of suppression of the height of azotobacter 9,7 mm is character for the isolates of the type A. flavipes (Bain. et Sart.) Thom et Church, while the isolates of the type A. niger v. Thegh, A. fumigatus Fres. Have 7,4 mm.
The phenomen of phytotoxicity, which is revealed by separated isolates of micromycetes not always coincide with antagonism to the azotobacter. To the most strong antagonists there are involved A. fumigatus Fres, A. alliaceus Thom et Church, A. flavus Lk., as suppressing of the azotobacter´s height and detaining of the winter wheat´s germination. By our facts A. alliaceus Thom et Church, which is separated also from other ecological zones of light-chestnut soils preserves toxic behavior.
Mechanic erosion rise the general number of micromycetes in the soil espessially the types of genera Реnicillium and Aspergillus. Micromycetes of the genus Mortierilla M. alpina Peyronel reveal sensitivity to the compaction of the soil and can be used as indicators of the ecological condition of the soil.
The use of heavy machines leads to the increase of the whole number of micromycetes in the soil, it especially reveals at the initial phases of the plants´ development. At the compacted by the agricultural machines soil there increases the content of mushrooms - antagonists to the 20% in comparison with the control, there decreases the whole biological activity and harvest of barley. But introduction of organic fertilizers restores the ecological environment.
The work was submitted to the international scientific conference "Nature management and protection of environment" (France, Paris) 15-22 of October 2010. Came to the editorial office on 14.09.2010.