Changes in soil carbon content and reserves under long-term field experiments in the steppe zone of the Southern Urals

Abstract

The identification of factors determining the stability of soil organic carbon is an important step in managing the volumes of greenhouse gases and crops entering the atmosphere. The greatest influence on the soil organic carbon (SOC) pool in the soils of agroecosystems is exerted by oxidation processes under intensive agrotechnical action, decomposition, mineralization and humification by soil microorganisms, and also transformation under the influence of enzymatic activity of soils. The studies were conducted on the sites of a long-term field hospital and virgin soil located in the zone of distribution of steppe chernozems of the Southern Urals. During field and laboratory studies, the intensity of soil emission of CO2 (adsorption method), the activity of peroxidase and polyphenol oxidase (colorimetric method), and the soil organic matter content (dichromateoxidationtechnique) were determined. The indicators of the content and reserves of soil organic matter in different experimental variants showed a high dependence on the intensity of mineralization processes as a result of active mechanical treatment, aeration and increased activity of microorganisms, as well as the activity of soil enzymes involved in the carbon cycle (C).