What is Humic Acid?

What the heck is Humic Acids?

For the sake of science at the expense of about ten bucks, I got ahold of a box of humic acids. It is sourced from oxidized lignite according to the website and it might help uptake micronutrients. What has interested me the most is the idea of increasing chelation of nutrients held in the soil for the plant to uptake. I'm going to utilize this in my seed starting mix because I can and see if I can passively notice any improvements.

Has anyone looked into Humic Acids and utilizing them in their soil improvement projects? Is it just a fad? Is Lignite it just essentially coal?

I don't have a strong grasp of the material and its potentials, I hope someone might be able to help me more firmly understand it.

We have Iron Chelate as a soil additive, are they the same?

Soluble source of Iron in EDTA Chelated form
Fast acting, effective and easily available to plants
Suitable for foliage spray for quick action
Economical package
This soluble EDTA form of Chelated iron is highly effective in overcoming iron deficiencies common in Garden plants including Fruits, Vegetables & Flowering plants. It acts quickly to correct leaf yellowing and stunted growth. Yellowing of new leaves or new growth is a typical symptom of Iron deficiency. If soils are highly alkaline, try to neutralise the soil for better uptake of iron and long term effectiveness of the product.
HUMIC ACID
Humic acid is a group of molecules that bind to, and help plant roots receive, water and nutrients.
High humic acid levels can dramatically increase yields.
Humic acid deficiency can prevent farmers and gardeners from growing crops with optimum nutrition.
or from wikipedia
Humic substances are coloured recalcitrant organic compounds naturally formed during long-term decomposition and transformation of biomass residues.
The colour of humic substances varies from yellow to brown to black.
Wikipedia

It’s literally just low-nutrient compost with all the good stuff leached out.

It’s outdated science. A hundred years ago a prestigious scientist came up with a theory that soil organic matter all simplified to a stable state called “humus,” after finding humic acid in soil by using an extraction process. At the time, a lot of knowledgeable people thought this was bunk and it was controversial, but it eventually caught on. University horticulture grads could set up businesses making and selling “humic acid” as a garden amendment.

Problem was, there were 100 years of field tests and this miracle garden amendment never actually caused any measurable improvements in garden or soil performance!

Then a couple years ago, some scientists went looking for humic acid in soil using modern means, and… drumroll, there was no humus or humic acid in terrestrial soil!

Turns out, the original researchers MADE the humus with the test the were using to measure it! Soil humus never existed, and humic acid is just low quality compost that won’t do much for garden performance.

Still, people are still selling it, and some gardening authors are still teaching people to use it.

(The original study showing that soil humus, does not in fact, exist. https://www.nature.com/articles/nature16069 This is now generally considered settled science and current soil science has moved on from the humus hypothesis.)

And I don’t often recommend this author, due to the political bias of his work, but it’s another source on the current understanding that soil humus does not exist. https://www.gardenmyths.com/humus-does-not-exist-says-new-study/

Some scientists still defend the term by saying “scientists talked about humus for 100 years so admitting that it doesn’t exist will hurt the credibility of soil science.” They say “we should just call whatever DOES exist in the real soil carbon cycle “humus” so we can keep talking about humus.”

But either way, the stuff in the box won’t do much for garden performance, and it’s best not to think about humus if you want to build great soil. The modern soil model is much more useful and practical for gardeners.

Humic and fulvic acids are the end of the line for carbon in living soil. If we think of trophic cascades, the primary production is organic matter that lands on the soil surface -- dead plant matter, manure, insect parts -- and it gets broken down by all the different invertebrates, bacteria, and fungi. Each consumer excretes some part of what it could not use, and then that passes through another, until there's no more metabolic potential left. At that point, what remains are dense chains of hydrocarbons interspersed with aromatic carbon rings.

On their own, humic products are like biochar. They're a reservoir of soil carbon that doesn't get eaten or broken down any further. But also like biochar, it's not just an inert substrate. Thanks to the carbon rings, they can do the same trick of pulling ions out of solution and holding on to them until something with more demand (typically fungi or bacteria) grabs them. So even though they're not contributing directly to soil fertility, they are providing a physical and chemical environment that enhances productivity around them.

One of the features of terra preta soils in the Amazon that the early research noted was the high levels of humic products, and these probably come from a combination of the trophic pathway and breakdown of incompletely "cooked" charcoal. If biochar is made at low temperatures and some of the volatile hydrocarbons are still in it, these decompose gradually and form humates as well.

So yes, it's a thing, but it's more an emergent property of fertile, productive soils than a primary cause, although it could be considered a catalyst for biological activity.