Inorganic Carbon: An Important Component in the Global Carbon Cycle of Steppe Soils

Seventy-six soils of the steppe zone of the East European Plain, including Chernozems and Kastanozems and Luvic Calcisols on the territory of over 900 000 km² have been studied. The content of total, organic, and inorganic carbon and their stocks were measured in soils. The data obtained show that the average reserves of inorganic carbon in the two-meter thickness of steppe soils is 165 t/ha, and that of organic carbon is 150 t/ha. The inorganic carbon stocks in the zone of distribution of Kastanozems and Luvic Calcisols exceed the content of organic carbon by more than two times. Further monitoring of the obtained results is necessary, which will make it possible to assess the speed and scale of changes in inorganic carbon stocks in soils under the influence of constantly changing climatic and anthropogenic factors.