The paper covers the problem with phosphorus supply at crops cultivation on sod-podzolic soils of Polissya region. Issues of P2O5 renewal in the arable soil layer of sod-podzolic soils were reviewed together with the relationship between the phosphorus balance and crop rotation productivity, as well as role of biological preparation Polymyxobacteryn at periodic and additional application of technical phosphorus.

The positive action of microbial preparation Microgumin on limitation by soil profile of biogenic elements and their compounds was proved in lysimetric experiments with spring barley. At the same time inoculation had promoted activation of nitrogen metabolism in plants which was proved by determination of plants’nitrate reductase’s activity and amino acids content in barley seeds.