Nitro Zlak — this is a bio-preparation containing bacterial suspension of Agrobacterium radiobacter and Bacillus megaterium. The viability of bacterial cells is not less than 2.0?109 CFU/ml of the preparation. The preparation is intended for use in agriculture. The sphere of application — cereal grass cultures. The bio-preparation can be used to protect plants from diseases and improve their growth due to the action of beneficial microorganisms contained in the composition. The preparation is applied within environmentally safe agricultural production methods.