Sequential chemical extractions of the mineral-associated soil organic matter: An integrated approach for the fractionation of organo-mineral complexes

► We propose a complete fractionation method for soil organic matter. ► The SOF method describes the stabilization of SOM by using selective extractants. ► The most of SOM is stabilized through weak bonds. ► The role of carbonates in SOM stabilization is unclear. ► A substantial fraction of SOM remains insoluble after all extractions.