<p>The <i>Bacillus</i> strains have long been widely and successfully used as the polyfunctional biologics’ basis in various systems for crops cultivation and protection. The research goal was to evaluate application effect from experimental prototypes of multirecycled polyfunctional biologics based on <i>Bacillus subtilis</i> I-5/12–23 together with compost in potato organic farming. The growth and development of potato plants of the Udacha variety showed substantial stimulation up to the flowering phase, regardless of the hydrothermal conditions during the growing season. The stimulation was by the additive effect of joint biologics and compost use in proportion to its dose. In the flowering phase, the biological efficacy with respect to the potato fungal diseases incidence and development was 90% under optimal hydrothermal conditions and up to 75% under drought conditions. Five-year scientific and producing approbation of the technological application rules for the biologics’ prototypes based on <i>B. subtilis</i> I5-12/23 and compost developed for the North-West region’s various climatic conditions showed their high efficacy in protecting the organic potato. Disease incidence on plants decreased by about 80%, on tubers by about 50%, their quality improved, and the marketable products yield increased at 9 t ha⁻¹ (3 t ha⁻¹, on average). The application’s technological rules optimizing for various climatic conditions are carried out by changing the consumption norms of protection means in proportion to the limiting factors. Multirecycled polyfunctional biologics prototypes combining the properties of biopesticides, biofertilizers and inoculants can be used to ensure stable organic potato production.</p>