I usually wouldn't post this sort of thing on here but thought this was a
sufficiently monumental piece of information to merit doing so...
>From a post by Toby Hemenway on FedBook:
Some amazing news on the soil science front. Humus doesn't exist. Several
recent articles are showing that humic and fulvic acids and many of the
other humic components of soil are artifacts of the alkaline treatment that
is used to measure humus content, and don't, in fact, exist in untreated
soil. When OM is measured using non-destructive methods such as NMR
spectroscopy, no humic compounds can be found. Organic matter does not
degrade into "stable" humic components, it simply decomposes into a
continuum of smaller and smaller carbon compounds. There is constant, slow
turnover of carbon in soils, not a semi-permanent trapping of carbon into
"humus." Humus, meaning a stable form of carbon visualized by alkaline
extraction, seems not to exist. It's an artifact of the lab method. This is
kind of blow-away news for those of us who teach soil science--and it's a
good lesson on how the methods we use determines what we see. Teachers,
start revising how you teach soils, and stop talking about humus.
Most of the articles on this are behind journal paywalls, but some of the
abstracts are available. One article is Lehmann, J.; Kleber, M.
(2015-12-03), "The contentious nature of soil organic matter", Nature
528:60-68. There is a short video based on that article linked below.
https://www.youtube.com/watch?v=-n6emCNEmKg
--
*In order to change an existing paradigm you do not struggle to try and
change the problematic model /* *You create a new model and make the old
one obsolete /* *That, in essence, is the higher service to which we are
all being called. //* Buckminster Fuller
