Microaggregate in soil: Current concepts, topics, and challenges in a nutshell

Microaggregate development and turnover and its linkage to the function of soils is a major research field in soil science. Microaggregates are deemed the most stable and persistent compound structures in soils and are conceptually considered as the fundamental structural building units of a – frequently even hierarchically structured – soil (Totsche et al. 2018). Most of the research on microaggregates has been motivated by the search for a better understanding of the storage and dynamics of soil organic matter. Fueled by the advent of instrumental analytical tools that allow to study soil structural and chemical heterogeneity, biodiversity and biogeography on the submicron scale, and expedited by the advancement of theoretical approaches for joint reconstruction and interpretation in-silico  recent direction changed: New foci are the formation, stability and turnover of microaggregates, their composite building units, the patterns of spatial allocation of the various inorganic, organic and biotic materials involved, and the role microaggregates might have in and for the functioning of soil. This presentation will give a compact overview on the current topics, challenges and concepts in microaggregate research and the role of microaggregates for the architecture, properties and functions of soils.