Radiocarbon dating pedogenic carbonates
Modern soils in the surrounding of Tell Chuera show carbonate precipitation in soil depths of about 40 cm, suggesting that the studied carbonate pendants were formed in similar depths. 10 to 30 cm below the soil surface, hence topsoil was probably eroded, possibly due to agriculture.
The tops of the remains of limestones, which serve as nuclei for carbonate precipitation, were capped.
In addition to soil fertility, SIC plays an important regulatory ecosystem service by sequestering atmospheric COSoil inorganic carbon (e.g., various types of carbonates) can be lithogenic or pedogenic in origin [25,26].
While lithogenic carbonates are considered rock derived, pedogenic carbonates can form as a result of dissolution and re-precipitation of lithogenic or newly formed carbonates .
An increase in the activity of carbon exchange processes, and, hence, the rejuvenation of radiocarbon dates, indicate the input of young SOM to the soils, while more ancient dates indicate a decrease in recent SOM.
This study was conducted to radiocarbon date the soil organic carbon (SOC) and quantify pedogenic carbonates in the Russian Chernozem at depth at three sites: a native grassland field (not cultivated for at least 300 years), an adjacent 50-year continuous fallow field in the V. Alekhin Central-Chernozem Biosphere State Reserve in the Kursk region of Russia (UNESCO—MAB Biosphere Reserve), and a cropland in the Experimental Station of the Kursk Institute of Agronomy and Soil Erosion Control.Most grasslands have undergone considerable changes due to human activities worldwide [1,2].Grassland soils of the world store significant amounts of soil organic carbon (SOC) and soil inorganic carbon (SIC), and many studies have used radiocarbon dating for determining carbon dynamics [3,4,5,6].Originally, it was thought that SIC required centuries to accumulate [27,28].Pedogenic carbonates were extensively studied in different types of soils primarily in various landscape positions [29,30].