We studied the microbial complex of soddy weak podzolic soil in potato's rhizosphere and estimated qualitative and quantitative composition of the “Ecostern” biodestructor used in combination of the cover crops and foliar application of biostimulants. The common technology of growing potatoes of the Pioneer variety was used to determine the impact of the stubble destructor on the formation of microbial biome. The following findings were made. The use of biodestructor “Ecostern” (1.2 l/ha) and the introduction of white mustard cover crop as a potato predecessor (compared to the variant without its application) contributed to the growth of the index of ecophysiological biodiversity from the range of expected to high values, increased the number of pedotrophs by 72-181%, microorganisms consuming organic forms of nitrogen by 16-36%, soil nitrification capacity by 130-160 % and photosynthetic productivity (Fv/Fmax) by 29%. However, at the same time the biological activity index was reduced by 69.4 points, and the total number of bacteria in the germination phase was reduced by 30%, and the number of ammonifying microorganisms was reduced by 5.5-87% which may be explained by a decrease in the pathogenic microorganisms' activity. A significant increase in the maximum value of chlorophyll fluorescence (Fmax) in potato leaves was registered after the use of the biodestructor. While the control value (without a biodestructor and biological products) was 1394.33 c.u., the introduction of biodestructor increased it up to 1786.67 c.u. with The highest level of Fv/Fmax – 0,67 c.u. of photosynthesis productivity was observed the complex application of the biodestructor “Ecostern” + “Mycohelp” + “Fitohelp”, which is 29% higher than the value in the control version, without biostimulators and biodestructor. The highest total number of bacteria in the rhizosphere of potatoes was registered at triple application of "Agat" 25 (100 ml/ha) and the use of "Mycohelp" (2.0 l/ha) and "Ecostern" , resulting in the increase of bacteria's number by 7.3-25% compared to the control. The following biostimulants had the greatest impact on the intensification of microorganisms involved in the carbon and nitrogen cycles: the number of pedotrophs - “Stimpo” (288%, the highest index), “Agat” without a biodestructor (+43%) and “Regoplant” with biodestructor (+44%); oligotrophic microorganisms – by combining “Mycohelp” with “Agat” and “Fitohelp” (13-71%). We registered the following impact upon the microorganisms of the nitrogen cycle in sod-podzolic soil: namely “Agat” on the background of “Mycohelp” increased the number of ammonifiers (7-71%), Azotobacter by 82-105% without destructor and by 45% with the use of destructor; “Fitohelp” and “Stimpo” combined with “Mycohelp” increased the number of Azotobacter by 23-88%. The use of “Ecostern”biodestructor at the rate of 1.2 l/ha on white mustard as a cover crop on soddy medium podzolic soil resulted into the increase in the availability of nutrients during the vegetation of potatoes. The said increase is supported by the value of the oligotrophicity coefficient below 1 (0.01-0.895) and the mineralizationimmobilization coefficient's approaching 1 (balancing the processes of synthesisdestruction of organic matter). Under organic farming, the course of biological processes in the soil ecosystem exceeded the control value. The achieved value is 0.6-2.6 CO^2 mg/kg of soil compared to intensive farming. However, both farming systems are significantly inferior in terms of respiration intensity to long-term fallow land, which is 6.5-11 times higher. The use of the stubble destructor “Ecostern” results into forming a 37 % wider molecular biological diversity of the prokaryotic metagenome compared to the control. Compared to the variants without the biodestructor, the amount of mobile phosphorus increased by 10%, the amount of potassium increased by 9-11 %, and acidity exchange decreased by 0.4-0.7 pH units. The number of soil aggregates of optimal size increased by 0.8%, the density of the solid phase decreased by 0.8 %, and the density of the structure decreased by 1.5 %, with a clear trend toward optimizing the soil's porosity and moisture capacity. Comparison of organic and intensive farming systems, as well as fallow land, showed that the latter formed a more developed profile with a more powerful humuseluvial horizon, the reaction of the soil environment became close to neutral, and the humus content and nutrient supply increased by 106%. The use of organic farming contributed to a 46 % increase in mobile forms of potassium under intensive technology. The use of the destructor “Ecostern” and the 4th variant (“Mycohelp” (2.0 l/ha) + “Fitohelp” (1.0 l/ha) (triple application) resulted into the highest average height of the stem of Pioner variety potato (48 cm), the size of the assimilation surface (4063 cm^2) and the weight of the bush (1763 g/bush).
