The prized organic material, i.e. stubble and straw, remains after grain harvesting, however, in order to produce the full-fledged fertilizer from it, it is required to accelerate the process of plant residues decay. In order to solve this task more efficiently, it is suggested to use the complex microbial preparation containing strains of microorganisms with lytic and antagonistic action. The Scientific Research Laboratory of Molecular Genetics and Biotechnology has developed the biological preparation Zhycen consisting of the mix of cultures of living cells of antagonist strains Pseudomonas sp.-11 and Bacillus sp.-49. The preparationis intended for acceleration of stubble remains decay in the fields. The action of the preparation is conditional on high cellulasic activity of the strains included into its composition. The experimental results of application of the preparation Zhycen obtained during microplot test have revealed that this preparationis able to accelerate the decay of stubble remains. The results have been assessed based on loss in straw mass wetted with 1 % solution of the preparation with the straw being stitched up into the small glass tissue sacks and placed into soil to the depth of 10 cm. The control sample has been treated with water. The generally accepted technology contemplating the introduction of nitrogen (in a form of ammonium sulphate) into soil has been modeled as reference. The results have been evaluated on the 42th day. The preparation efficiency reflecting thes traw degradation level has reached 45% exceeding the results of control sample by 33%, and the results of the sample treated with 0.01 Мsolution of (NH4)2SO4by6 %. Visualand organoleptic examination has allowed establishing that the straw treated with Zhycenhas changed the structure significantly, has become more fragile upon mechanical effect (attrition by hands). The straw treated with the preparation sample has had no mold deteriorate foci. It has been established that the preparation Zhycen suppresses phytopathogenic microorganisms both in pure culture and in soil samples. It has been revealed that strains of Botrytis, Fusarium fungi and some species of Alternaria are more sensitive to the action of the preparation. Zhycen suppresses the growth of such fungi species by 60-76 %. Maximum area of bacteriostasis has been observed in Erwinia aroideae and Clavibactersp. Erwinia atroseptica has been found to be insensitive to the preparation. The effect of Zhycen on general phytotoxicity of soil has been assesses based on changes in growth indicators of test crop (barley) upon its cultivation in soil treated with the preparation under study. It has been shown that the treatment of the soil with 1 % solution of Zhycen allows reducing of such indicator: germinative energy and germinating ability of barley have increased by 11 % as compared to control samples of soils, and the length of germs has increases by 23.1 % in average. The preparation Zhycen is recommended for application as follows: after harvesting, the chopped straw should be evenly distributed throughout the plot. Then stubble residuess hould be treated with 1 % solution of microbial preparation in the amount of 3 l/ha, process solution rate should be 300 l/ha, and after that the straw should be disked.