TY  - JOUR
AU  - Siebers, Nina
AU  - Abdelrahman, Hamada
AU  - Krause, Lars
AU  - Amelung, Wulf
TI  - Bias in aggregate geometry and properties after disintegration and drying procedures
JO  - Geoderma
VL  - 313
SN  - 0016-7061
CY  - Amsterdam [u.a.]
PB  - Elsevier Science
M1  - FZJ-2018-02001
SP  - 163 - 171
PY  - 2018
AB  - Isolation and drying soil microaggregates and their building units are of crucial importance when studying their structure and function within different soil management systems. Our aim was to evaluate how different drying techniques preserve small aggregate building units after different disintegration steps. After applying fast wetting, slaking, or ultrasonic dispersion at 440 J mL− 1 to Cambisol topsoils under either long-term forest, grassland, or arable soil management, aggregate-size distributions were assessed using fast image analyses after optical particle-size assessment prior and after air- and freeze-drying. Microaggregates isolated by dry-sieving served as control. While ultrasonic dispersion significantly disintegrated soil aggregates into smaller units, slaking in water did not. Intriguingly, freeze-drying preserved the aggregate size distribution fairly well, with a reaggregation ranging between 1.2 and 10.1%. In contrast, air-drying led to substantial reaggregation of particles ranging between 20.4 and 44.9%. However, freeze-drying also led to slight deformation of particles and also to a redistribution of elements between size-fractions, the extent of which being different for the samples under different land-use. We conclude that ultrasonic treatment followed by freeze-drying is suitable to preserve the correct aggregate size of at least Cambisols, but the properties of the secondary particles may still not reflect true geometric forms and chemical properties.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000424179800016
DO  - DOI:10.1016/j.geoderma.2017.10.028
UR  - https://juser.fz-juelich.de/record/844597
ER  -