Articles | Volume 17, issue 3
Biogeosciences, 17, 683–698, 2020
Biogeosciences, 17, 683–698, 2020

Research article 10 Feb 2020

Research article | 10 Feb 2020

High-pH and anoxic conditions during soil organic matter extraction increases its electron-exchange capacity and ability to stimulate microbial Fe(III) reduction by electron shuttling

Yuge Bai et al.

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Cited articles

Abelmann, K., Kleineidam, S., Knicker, H., Grathwohl, P., and Koegel-Knabner, I.: Sorption of HOC in soils with carbonaceous contamination: Influence of organic-matter composition, J. Plant Nutr. Soil Sc., 168, 293–306,, 2005. 
Achard, F. K.: Chemische Untersuchung des Torfs, Chem. Ann. Freunde Naturlehre, Arzneigel. Hausalt. Manufact, 2, 391–403, 1786. 
Aeschbacher, M., Sander, M., and Schwarzenbach, R. P.: Novel electrochemical approach to assess the redox properties of humic substances, Environ. Sci. Technol., 44, 87–93,, 2010. 
Aeschbacher, M., Graf, C., Schwarzenbach, R. P., and Sander, M.: Antioxidant properties of humic substances, Environ. Sci. Technol., 46, 4916–4925,, 2012. 
Aiken, G. R.: Humic substances in soil, sediment, and water: geochemistry, isolation, and characterization, Wiley, New York, 1985. 
Short summary
Biogeochemical processes of SOM are key for greenhouse gas emission and water quality. We extracted SOM by water or by NaOH–HCl under oxic–anoxic conditions. Chemical and anoxic extractions lead to higher SOM electron exchange capacities, resulting in stimulation of microbial Fe(III) reduction. Therefore, aqueous pH-neutral SOM extracts should be used to reflect environmental SOM redox processes, and artifacts of chemical extractions need to be considered when evaluating SOM redox processes.
Final-revised paper