The biological addition to organic-mineral fertilizers contains two bacteria associations taken in the ratio 1–2:0.5–1, with one of the associations containing Azotobacter chroococcum and Beijerinckia fluminensis nitrogen binding bacteria in the ratio 1–0.5:1–0.5 and the other association containing Bacillus megaterium and Bacillus mucilaginosis bacteria, which decompose phosphorus- and potassium containing compounds, in the ratio 1–5:0.5–2, as well as a preservative and micro- and macroelements.