PM

Soil functions are decisively related to the structure of soil microaggregates. Thus, the understanding of soil processes and functions also requires a concept of the formation and consolidation of soil structural elements.

We develop such a general model framework including the interactions of prototypic building units, as e.g., specific minerals and/or organic matter.

The identified and implemented relevant aggregation processes include electrostatic forces, attraction by gluing and cementing agents, geochemical reactions, or diffusion. They are taken into account in a mechanistic framework using cellular automaton rules and non‐linearly coupled systems of partial differential equations with algebraic constraints. The resulting microaggregate structures are investigated quantitatively by morphological analysis that provides comprehensive insights into structural similarities found for aggregates formed under various conditions. With that we heuristically investigate effects of the prototype composition, charge, size ratio, and concentration on microaggregate formation. Moreover, the model permits to illuminate the temporal evolution of aggregate formation in multiple scenarios and therefore provides estimates of soil aggregation behavior in case an observation is inhibited by experimental limitations. The numerical implementation uses advanced discontinuous Galerkin methods and a massively parallel implementation.