PSXI-21 - Soil emission of carbon dioxide and behavior of microorganisms in soils of Western Kazakhstan

Kazakhstan Western ecosystems are intensively used in agricultural production. Assessing greenhouse gas emissions from soils, especially CO2, is important. In the upper stages, microbiology, characteristics and condition of the soil change. Biological intensity indicators are soil respiration processes, numerous microbiocenoses species composition. Soil CO2 emissions were measured 5 times monthly during three years. The CO2 flow rate from soil surface is measured by a closed dynamic chamber method with Li-8100A field respirometer. Metagenomic soil testing used bacteria DNA, archaea, real-time PCR, 16SrRNA sequencing. The soil CO2 monthly dynamics fluxes varied among the lands, within the season. In 2020, the CO2 emissions soil peak noted in the pasture. There is a slight decline in summer with a decrease towards the cold season. Comparison between the CO2 flux pasture soils is less in virgin soil. The minimum CO2 flux was recorded in November - February; in the spring, the flux increases. The above CO2 emissions were recorded in summer. In soils, there is wide variety of microorganisms with opposite and incompatible properties for one habitat. The microbial communities structure identified at the family level. The taxonomic samples structure ominated by phylae - Actinobacteria, Proteobacteria, Chloroflexi, Acidobacteria, Gemmatimonadetes, Firmicutes, Actinobacteria. The spread explained by increased actinomycetes resistance characteristic to low moisture content with long dry period. For comparative evaluation microbial communities results comparing by cenoses of upper horizons with dark chestnut soil indicators. This violation caused microorganisms resistance to disturbing factors. On anthropogenically disturbed saline soils, the bacteria found were specific and resistant to critical conditions. CO2 emission in soil varied cenosis type. The CO2 intensity factors were precipitation deficit, high temperature. The profile microorganisms distribution corresponded to the soil horizons humus content. During summer soil drying, the deep soil horizons abundance occurred where moisture is retained.