Hi ECOLOGers I’m collating a discussion on the issue of whether or not soil humus really exists, in light of Lehmann and Kleber’s 2015 Nature paper (referenced below), and others using more advanced molecular profiling technology rather than traditional extraction procedures.
There’s quite a bit of push-back from a couple of proprietary scientists that feel the soil humus concept is conceptually useful enough to be retained; I disagree but would like to hear from others with (far) more experience than I have in this area. Are there any soil scientists out there that would be willing to contribute their thoughts on this issue? Either here or on a short call if there’s time. Here are a few key references I’m working from (mainly as examples; there are several dozen others drawn from the references cited therein): Lehmann, J., & Kleber, M. (2015). Perspective The contentious nature of soil organic matter. Nature, 528(7580), 0–8. http://doi.org/10.1038/nature16069 Miltner, A., Bombach, P., Schmidt-Brücken, B., & Kästner, M. (2012). SOM genesis: Microbial biomass as a significant source. Biogeochemistry, 111(1–3), 41–55. http://doi.org/10.1007/s10533-011-9658-z Gleixner, G. (2013). Soil organic matter dynamics: A biological perspective derived from the use of compound-specific isotopes studies. Ecological Research, 28(5), 683–695. http://doi.org/10.1007/s11284-012-1022-9 Sutton, R., & Sposito, G. (2005). Critical Review Molecular Structure in Soil Humic Substances : The New View. Environmental Science & Technology, 39(510), 9009–9015. http://doi.org/10.1021/es050778q Kallenbach, C. M., Grandy, A., & Frey, S. D. (2016). Direct evidence for microbial-derived soil organic matter formation and its ecophysiological controls. Nature Communications, in revisio, 1–10. http://doi.org/10.1038/ncomms13630 (Book as PDF chapters) Andreux, F. (1996). Humic Substances in Terrestrial Ecosystems. Humic Substances in Terrestrial Ecosystems, 45–100. http://doi.org/10.1016/B978-044481516-3/50003-7 Knowledgeable perspectives, additional recommended references or further thoughts on this issue would be very much appreciated. Best regards, Susan Cousineau Cell: (805) 819-9182 M.Sc. Evolution 2012 (France/Netherlands) BSc. Ecology Hon 1st, U Calgary, Canada (2010) “The master in the art of living makes little distinction between his work and his play, his labor and his leisure, his mind and his body, his information and his recreation, his life and his religion. He hardly knows which is which. He simply pursues his vision of excellence at whatever he does, leaving others to decide whether he is working or playing. To him, he’s always doing both.” - - - J. Michener
