Bryant, thank you for this thread. I have to say I find some of what you've said confusing, particularly
"If you want to find humus you have to look for it in a laboratory setting since out in nature it disappears almost as quickly as it forms.
... Once humus is created, it immediately binds with those molecules and atoms that make up the inorganic parts of soil at that instant, humus is gone."
I am not a soil scientist myself but I've been attending conferences and classes and reading on the subject for over a decade, and what you said above seems to fly in the face of other definitions that humus is the most stable
form of organic matter and can last for centuries. Your assertion that humus is not organic matter because the organic matter has decayed away is nonsensical, since organic matter is defined as being created by life processes, and decay is a life process. If decay were what created humus, then humus would by definition be organic matter.
However, I've attended half a dozen lectures and classes by Dr. Christine Jones (amazingcarbon.com) who discovered what she calls the "Liquid Carbon Pathway," namely that humus is formed exclusively in the presence of plant root exudates and not
from decaying organic matter. She did an experiment that, as I recall, involved radioactive carbon in the form of CO2 that got absorbed by living plants and passed by them into the soil, but when those radioactive plants were cut down and placed in a chamber with fresh soil and no living plants, the radioactive CO2 went back into the air as the plants decayed and not into the soil. Unfortunately I'm not able to find a description of this experiment to cite; I just remember it from her lecture.
She likened humus to a house that is built intentionally by microbes for storing nutrients and for living in; far from being "gone" when it binds with nutrients, that is when it fulfills its function. It is a product of decay only in the same sense that a stick-frame house is a product of the decay of forests! Yes, the trees break down into lumber before they reassemble into houses, but it's not a passive decay process, it's an intentional construction process. Being like a house, there is no precise chemical formula for building humus, just a general specification that can be met by thousands of different arrangements of chemicals.
The microbes that build humus can also live in the honeycomb structure of biochar, which is why adding biochar to soil (along with living plants and their microbiomes) causes an increase in humus: the microbes live in the biochar temporarily while they are constructing humus to live in long-term.
In more recent lectures Dr. Jones has advocated preserving organic matter with anaerobic lactobacillus fermentation (basically making silage) instead of aerobic composting, so that the carbon stays in the soil until plants' microbiomes can convert it to humus and other stable compounds, rather than escaping into the atmosphere.
I agree that there is a lot of misinformation about humus, and I admit I may be repeating some myself, but I suspect you are not immune from this either.
Thank you again for the conversation.
Kansas Permaculture Institute