Formation of biogeochemical interfaces in soils as controlled by mineral and organic components.

The formation of soil interfaces is controlled by the type of particle surfaces present and the assemblage of organic matter and mineral particles. The formation of interfaces was studied with artificial soils which were produced in a long-term biogeochemical laboratory incubation experiment (3 and 6 months). The experiment used clay minerals, iron oxides and charcoal as major model components controlling the formation of interfaces because they exhibit high surface area and microporosity. Soil interface characteristics are analyzed in relation to microbial community structure and function that developed after 6 months of incubation. Already after 6 months of incubation the artificial soils exhibited different properties in relation to their composition. Major effects are observed for artificial soils formed in the presence of montmorillonite, ferrihydrite and charcoal.