In model incubation experiment the effect of various agrocenoses on CO₂ production and nitrogen-mineralizing ability of the soil to accumulate nitrate nitrogen (N-NO3) was investigated. It was shown that the rates of mineralization of soil organic matter decreased from the first record taken to the last in the following order (in percent): 57 → 63 → 68, further observation of CO₂ emissions led to a smoothing of redox reactions. The use of mineral fertilizers in comparison with agrocenoses without fertilizers increased CO₂ emissions by 15–24%, depending on the studied variant. It was noted that the agrocenosis with the alienation of aboveground biomass of straw exerted the least load on the total mineralization of soil organic matter – on average, in two levels of fertility, it was 489 mg C / kg. The use of analysis of variance in the experiment did not reveal significant differences in the interaction of signs on the accumulation of N-NO₃, however, the solution of correlation and regression dependences contributed to finding a close relationship. It was determined by the capabilities of leached chernozem to compensate losses and restore the carbon-nitrogen potential of the soil. A similar consequence increased in the agrocenosis with mineral fertilizers and with a greater flow of aboveground and underground plant residues into the soil, the maximum CO₂ emission was registered in the variant 634 mg C / kg, and high statistical indicators of the studied signs were established.