Accumulation of Atmospheric Carbon by Crop Rotation Crops and the Effect of Fertilizer Systems on the Accumulation of Organic Carbon by Arable Sod-Podzolic Soil

Experimental data on the accumulation and loss of organic carbon in sod-podzolic soil over 6 rotations of a long stationary experiment are presented. It was found that during the growing season during photosynthesis, spring barley plants were bound into organic compounds 2.84–3.25 t/ha from the atmosphere (10.3–11.6 t CO₂/ha) during the growing season, meadow clover of the second year of use – 4.23–5.19 t C/ha (15.1–18.6 t CO₂/ha) depending on the experience options. During the rotation of the 8‑field crop rotation, cultivated crops were sequestered from the atmosphere 82.28–99.31 tons of CO₂/ha or 22.4–27.1 tons C/ha, depending on the soil fertilization system. Long-term use of arable land without fertilizers led to a decrease in the carbon content in the soil by 13.5% relative to the initial level. The soil of the stationary experiment was characterized by the maximum content and reserves of organic carbon when the arable land was saturated with manure at a dose of 20 t/ha and an equivalent amount of NPK. The carbon content for 6 rotations of crop rotation increased in the 0–20 cm layer by 15% of the initial one, carbon reserves in this layer increased by 5 t/ha, in the 0–100 cm layer – by 32.0 t/ha. The average value of the carbon-protective capacity of the studied soil varied from 29 to 31 g/kg in a layer of 0–20 cm of soil and did not depend on the applied fertilizer systems. The quantity and qualitative composition of biomass entering the soil with its various fertilizers had a significant impact on the accumulation of organic carbon.