Evidence linking calcium to increased organo-mineral association in soils.

ABSTRACT: Geochemical indicators are emerging as important predictors of soil organic carbon (SOC) dynamics, but evidence concerning the role of calcium (Ca) is scarce. This study investigates the role of Ca prevalence in SOC accumulation by comparing otherwise similar sites with (CaCO₃-bearing) or without carbonates (CaCO₃-free). We measured the SOC content and indicators of organic matter quality (C stable isotope composition, expressed as δ ¹³C values, and thermal stability) in bulk soil samples. We then used sequential sonication and density fractionation (DF) to separate two occluded pools from free and mineral-associated SOC. The SOC content, mass, and δ ¹³C values were determined in all the fractions. X-ray photoelectron spectroscopy w

SUBMITTER: Rowley MC 

PROVIDER: S-EPMC8550578 | biostudies-literature | 2021

REPOSITORIES: biostudies-literature