Dynamics of CO2 emission when introducing fallow lands into circulation

Abstract

The results of CO2 flows variability from fallow land soils, when they are introduced into circulation in the Western Siberia steppe are described in the present paper. The purpose of the research consists in studying the dynamics of CO2 emission by meadow-chernozem solodized fallow solonetzes when they are introduced into circulation with the use of various technologies. The research was carried out in Tarsky district of the Omsk region in 2023. The soil type: meadow-chernozem solodized solonetz (medium, low-sodium, columnar); slightly loamy and medium- degree loamy in terms of granulometric composition; and low-sodium content in terms of exchangeable-sodium content (7-15.5% of cation- exchange capacity (CEC)). Solonetz is an alkali soil characterized by low degree of soda-sulfate salini-zation. Based on obtained data for carbon dioxide emission from the soil of key land plots, the authors developed models of CO2 emission from soil depending on a technology used to introduce the fallow land into circulation on the solonetz. Significant correlation (r ˃ 0.50) throughout a year were obtained for emission (E) by key land plots with soil temperature. Moisture content of soil exerted lesser-degree influence on emission value. Agrotechnical technology for introducing fallow lands into circulation contributed to higher CO2 emission than the combined one. Compared to the reference land plot, CO2 emission increased by 1.17 times when using agrotechnical technology and by 1.09 times when using combined technology.