THE SILICATE RHIZOSPHERIC BACTERIA CAPABLE OF DECOMPOSING SOIL MINERALS WITH THE RELEASE OF NUTRIENTS ARE A PROMISING RESOURCE FOR CREATING BIOFERTILIZERS TO MAINTAIN SOIL FERTILITY AND STIMULATE PLANT GROWTH. THE MODEL EXPERIMENTS HAVE EVALUATED THE EFFECT OF THE SEPARATE AND COMBINED ACTION OF THE BIOFERTILIZER PREPARED ON THE BASIS OF SILICATE BACTERIA AND PEAT AS A CARRIER, AND THE NITROGEN FERTILIZER ON THE NUTRIENTS CONTENT IN BRASSICA JUNCEA (L.) CZERN (BROWN MUSTARD) AND SOIL, AS WELL AS THE MORPHOPHYSIOLOGICAL PARAMETERS OF THE STUDIED SPECIES. THE STRAIN OF SILICATE BACTERIA WITH PLANT GROWTH PROMOTING ACTIVITY WAS ISOLATED FROM THE RHIZOSPHERIC SOIL OF TUSSILAGO FARFARA L. ON ZAK'S AGAR NUTRIENT MEDIUM AND IDENTIFIED AS BACILLUS MEGATERIUM . B. JUNCEA PLANTS WERE GROWN IN POT CULTURES FOR 60 DAYS UNDER NATURAL LIGHT. THE ADDITION TO THE SOIL OF BOTH BIO- AND NITROGEN FERTILIZERS CONTRIBUTED TO THE IMPROVEMENT OF THE B. JUNCEA GROWTH PARAMETERS. THE MAXIMUM POSITIVE EFFECT WAS OBSERVED WHEN THEY WERE APPLIED TOGETHER: THE SHOOT HEIGHT WAS INCREASED BY 2.0 TIMES, BIOMASS - BY 4.0 TIMES, THE NUMBER OF FRUITS - BY 5.6 AND SEEDS - BY 1.6 TIMES. AT THE SAME TIME, THE CONTENT OF BIOGENIC ELEMENTS IN THE ABOVEGROUND BIOMASS PER PLANT WAS ALSO INCREASED: NITROGEN BY 7.0 TIMES, PHOSPHORUS AND POTASSIUM BY 2.0 TIMES. IT WAS SHOWN THAT THE BIOFERTILIZER BASED ON SILICATE BACTERIA INCREASED THE CONTENT OF AVAILABLE PHOSPHORUS IN THE SOIL, PROBABLY DUE TO THE SOLUBILIZATION OF ITS INACCESSIBLE FORMS. AT THE END OF THE EXPERIMENT, THE NUMBER OF COLONY-FORMING UNITS IN SOIL SAMPLES WITH THE APPLIED BIOFERTILIZER WAS 200 TIMES HIGHER THAN IN THE CONTROL, WHICH INDICATES THE VIABILITY OF SILICATE BACTERIA. THE ANALYSIS OF MORPHOPHYSIOLOGICAL CHARACTERISTICS, SUCH AS THE NUMBER OF CELLS AND CHLOROPLASTS PER UNIT AREA OF THE LEAF AND THE CONTENT OF PHOTOSYNTHETIC PIGMENTS, SHOWED THEIR INCREASE (2.0 TIMES ON AVERAGE). BASED ON THE RESULTS OBTAINED, IT WAS CONCLUDED THAT IT IS EXPEDIENT TO USE SILICATE RHIZOSPHERIC BACTERIA IN COMBINATION WITH THE NITROGEN FERTILIZER.