The paper presents the results of lyzimetric and field studies on the impact of microbial preparations Microhumin and Polymyxobacteryn combined with mineral fertilizers on the productivity of sugar sorghum in Polissya region. It was shown that the pre-sowing seeds bacterization had increase crops yields by 5 – 9% and increased output of ethanol by 0.3 t/ha. Application of biological preparations had ensured less reduction of water-soluble humic substances by 28 – 32%, nitrogen (nitrate) – by 11 – 15%, calcium – by 7%, magnesium – by 8 – 15%.