Reproduction of Fertility of Ordinary Carbonate Chernozem in the Case of Application of Straw and Humic Preparations
The influence of treatment of winter wheat straw with humic preparations ВІО-Don and BIO-Don-15 and of the application of mineral nitrogen in the compensating dose on the dynamics of straw transformation in ordinary carbonate chernozem was studied in a laboratory experiment. The stimulating effect of the application of the compensating dose of mineral nitrogen and humic preparations on the microbiological processes of straw transformation was determined. The treatment with humic preparation BIO-Don-15 and application of ammonium nitrate increased the degree of cellulose decomposition 1.7 and 1.9 times respectively, compared with the control. The proportion of mobile humus and fulvic acids in fractional-group composition increased, which indicated active humification processes in the soil. Humification processes reached a maximum in 5-7 months of composting straw with soil, after which the processes of mineralization began to predominate. In connection with this, the accumulation of humus occurred at the initial stages of composting straw with soil, and subsequently, its content decreased. In the variants with BIO-Don-15 humic preparation and with mineral nitrogen, the largest content of mobile humus was observed throughout the entire experiment. It was shown that the use of BIO-Don-15 had a positive effect on the accumulation of mineral forms of nitrogen and available phosphorus, not inferior to the action of the compensating dose of nitrogen; in this case, the costs were lower in comparison with the application of ammonium nitrate. The use of BIO-Don-15 for the treatment of straw provided more efficient use of stubble residues and by-products of cereals to optimize the fertility of arable soils.