REGULATION OF NITROGEN-CARBON INTERACTIONS IN AGROECOSYSTEMS IN THE FOREST-STEPPE ZONE OF UKRAINE

Aim. To determine the specified parameters of the complex model of nitrogen-carbon circulation while using different types of crop rotation, kinds of organic fertilizers and ways of soil cultivation in agroecosystems of the forest-steppe zone of Ukraine. Methods. Field, laboratory, computational, mathematical and statistical. Results. Specific types of organic fertilizers affect the emission of CO2 into the lowest atmospheric layer: in case of humus the typical emission interval is 25-85 t/ha, while in case of secondary products it is 70-160 t/ha. The impact of the way of chernozem preparation on nitrogen-carbon circulation is manifested in the fact that in case of subsurface tillage the carbon balance in soil was positively increasing compared to ploughing. The interval of CO2 emission into the lowest atmospheric layer due to the mineralization of humus and organic fertilizers with ploughing changes in a wider range compared against subsurface tillage. Conclusions. The nitrogen-carbon interactions are impaired due to the introduction of humus and removal of secondary products beyond the boundaries of the agroecosystem in the course of ploughing. The application of ground secondary products of crop production as organic fertilizers, wrapped up into the surface layer of chernozem during the subsurface tillage of soil, simulates the natural course of nitrogen-carbon circulation in agroecosystems of different types. Natural soil formation process is simulated due to the activation of photosynthetic activity of cultivated crops with CO2 saturation in the lowest atmospheric layer, which provides for extensive restoration of chernozem fertility in the forest-steppe zone of Ukraine.