Do soil aggregates really protect encapsulated organic matter against microbial decomposition?

authored by: Marc O. Goebel, Susanne K. Woche, Jörg Bachmann
Abstract: Soil aggregates can provide an effective protection of organic matter against microbial decomposition as reported by several macroaggregate disruption studies. However, research on the role of aggregation for carbon mineralization was mainly focused on arable soils. In the present study we aim to clarify the impact of aggregation on organic matter protection by measuring carbon mineralization in terms of microbial respiration rates of intact macroaggregates (2-4 and 4-8 mm) and corresponding crushed aggregates from seven topsoil horizons from both arable and forest sites. For two arable and one forest soil we found a significantly (P < 0.001) lower carbon mineralization from intact aggregates as compared to the corresponding crushed material. The portion of aggregate protected carbon reached up to 30% for a grassland soil. For the other arable and forest soils no significant effect of aggregation was found. Similarly, no clear trend could be found for the protective capacity of different size fractions. We conclude that protection by aggregation is effective primarily for soils with a large pool of labile organic matter regardless of their usage as arable land or forest.
Organisation(s): Section Soil Physics
Institute of Soil Science
Type: Article
Journal: BIOLOGIA
Volume: 64
Pages: 443-448
No. of pages: 6
ISSN: 0006-3088
Publication date: 06.2009
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Ecology, Evolution, Behavior and Systematics, Biochemistry, Animal Science and Zoology, Molecular Biology, Genetics, Plant Science, Cell Biology
Sustainable Development Goals: SDG 15 - Life on Land
Electronic version(s): https://doi.org/10.2478/s11756-009-0065-z (Access: Unknown)