The role of clay content and mineral surface area for soil organic carbon storage in an arable toposequence

Abstract Correlations between organic carbon (OC) and fine mineral particles corroborate the important role of abundance soil minerals with reactive surfaces to bind increase persistence matter (OM). The storage OM broadly consists particulate mineral-associated forms. Correlative studies on impact mostly combined data from differing sites potentially confounded by other environmental factors. Here, we analyzed in a clay content gradient 5–37% similar farm management composition. Throughout gradient, soils contained 14 mg OC g −1 average bulk without showing any systematic increase. Density fractionation revealed that greater proportion was stored as occluded high (18–37% clay). In low (5–18% clay), fractions had up two times higher contents than soils. Specific surface area measurements more related loading. This suggests there is thicker accrual at same within With increasing content, forms lower implies studied agricultural driven decoupled limitations.