Carbon balance in crops on typical chornozem and drained peat soils of the Forest-Steppe

Abstract

Goal. To establish the carbon balance in crop rotations on typical chornozem and drained peat soils of the Forest-Steppe based on comparing the yield of the total biomass of crops and the intensity of the allocation of CO2 from the soil surface to determine its impact on the environment. Methods. Field (for morphological comparisons and determination of crop productivity), adsorption (laboratory) (to determine the composition of nutrients in plants), and variational statistics of data (to establish the reliability of the data obtained using a specialized statistical data processing program Statistica). Results. The research was conducted on the typical chornozem and drained peat soils of the Panfyly experimental station of the Research Center «Institute of Agriculture of NAAS» during 2023–2025. The total yield of dry biomass in winter wheat crops in different varieties was 12.6–17.1 tons/ha, and absorbed carbon — 5.54 ± 1.1–7.52 ± 1.3 tons/ha, corn for grain — respectively, 21.0 and 9.24 ± 1.6 tons/ha. In sunflower and soybean seeds, these figures were, respectively, 11.5 and 5.06 ± 0.9, as well as 7.6 and 3.32 ± 0.6 t/ha, and in purple echinacea — 11.9 and 5.24 ± 1.0 t/ha. On drained peat soils, the total yield of biomass of perennial grasses (old-growth grass stands) was 14.5 t/ha for carbon absorption at the level of 6.38 ± 1.1 t/ha, and corn for grain — respectively, 18.3 and 8.05 ± 1.2 t/ha. The intensity of the release of CO2 from the soil surface depended on the culture, the phase of vegetation, the period of day, the air temperature, and averaged 3.4 ± 0.5–4.8 ± 0.7 kg/ha per day on chornozem. On drained peat soils in crops of perennial grasses and corn, this figure reached 8.1–8.8 ± 1.1 kg/ha per hour; at night it was 17–21% lower than in the daytime. The carbon balance on typical chornozem was positive in crops of winter wheat, corn for grain, and echinacea. Sunflower cultivation was also not a source of CO2 pollution. The balance had a small negative value (– 1.13 ± 0.2 t/ha) only in soybean crops. The use of drained peat soils for crops of old low-productive meadow lands and corn was problematic from an ecological point of view. Conclusions. The carbon balance determined by the adsorption method showed that the agricultural use of land in the Forest-Steppe zone in crops of corn, winter wheat, echinacea, and sunflower was not a source of pollution of the environment with carbon dioxide. Old low-productive meadow lands and corn crops on drained peat soils release more carbon into the environment than they absorb. However, these lands in the structure of the state’s acreage are insignificant (up to 1%).