Assessing the variability of soil microaggregates

• Applicants: Professor Dr. Wulf Amelung; Dr. Silvia Richter
• Subject Area: Soil Sciences
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 549390423

Soil microaggregates are stable subunits within the continuum of soil structure, but whether their properties and composition follow recurrent patterns has eluded researchers. Here, we use large microaggregate samples (100–250 µm) from four different soils (Luvisols, Chernozems, Ferralsols, Andosols) to test i) to what degree there is a variation in the density of individual microaggregates within the aggregate size class of a given soil, ii) to elucidate to which degree this variation in microaggregate densities differs among the soils of the selected reference soil groups, iii) to assess how the density of the individual microaggregates correlates with their content of major elements for the different soils, and iv) to investigate whether and to what degree microaggregates with same size and density also exhibit similar spatial element spatial pattern. To test these hypotheses, we will assess the density and element distribution of individual large microaggregates isolated from the different soils by confocal laser scanning microscopy (CLSM) and electron microprobe microanalyses (EPMA), and elucidate for each soil whether the properties of the large microaggregates are rather normally distributed or whether they cluster at certain values, controlled by their element contents or pattern.

• DFG Programme: Research Grants