It's my understanding that compost and humus are both organic matter in soil but compost is humus but humus might be something other than typically created compost. Such things as leaf mold under deciduous trees, or animal manures where they are deposited, or dead and decomposed animals in the forest, or almost any organic thing becomes humus when it decomposes. It's an important part of soil which contains good soil building organisms, soil nutrients, and moisture retentive properties.

I think of compost as a product of planned decomposition of organic matter.

I'll be interested to hear other's comments on this.

There are probably complicated scientific answers to this question but I really like LG's explanation.

Lloyd

I would venture to say that humus is the natural product of OM sitting on the ground. Compost will turn into humus after it's worked on by the biota. I've been reading Sir Albert Howards The Waste Products of Agriculture
Their Utilization as Humus. It's very informative and a pretty good read.

It's also available as a pdf download from the Agricultural Library

Chemically, humus consist of humin, humic acid, and fulvic acid. These are chemically stble endproducts of lignin (from wooody tissue) and polyphenols (tannins etc in leafs) in combination with nitrogen. Humin and humic acid are dark brown.

Humus also refers to the dark brown, soft fine crumbly result of vegetative decay, commonly seen under decaying leaves in the woods.

So compost has alot of humus in it no matter how you look at it, but compost is not humus.

And when my spelling is not so good it is a tasty dish made out of garbonzo beens.

The link has some good information that should sort out the difference.

Here is a link that might be useful: Soil Humic Substances

Humus is the residual organic matter in your soil. It is waht the soil bacteria do not digest right away. It is what is left of organic matter, compost, after the soil bacteria digest all they want, unless there is nothing more for them to work on and then they will digest that humus.
If you have a choice between compost and humus and, especially, if the humus has a higher price pass it by.

"Humus," as sold in bags, is a marketing ploy.

It takes years and years and more years to make real humus.

Would peat moss be considered a type of humus? It is not a great choice in my area for soil amending since it is not benefitial to red clay soil.

"Humus," as sold in bags, is a marketing ploy.

Here in Alberta we can buy humate in bags. A 25 kg. (55 pounds) bag is about $10.

Humate generally refers to the combined components (humic, fulvic and humin) along with its natural carrier (peat, coal, compost, etc.) Sometimes, humates are referred to as humic substances. The Alberta variety is mined from oxidized coal beds and called humalite. The other name for this mineral is leonardite.

Yes Jean, you can buy humus in bags.

Here is a link that might be useful: Humic matter in soil and the environment

Peat moss is not humus. Peat moss is a non renewable resource, just ask Ken Druse.
Since there is nothing to regulate the use of the word humus or humates people can package anything and put a label on it and call it "humus" or "humates" adn charge you an arm and a leg for it. Since you know that coal is not good for your soil why in earth would you pay someone money for a bag of coal that is now labeled "Humate"?

for a good reading on humus, ect., AcresUSA.com has a lenghthy arceive of articles and in 2004 had two articles about humus. I hope everybody will check the site out.
Further, I do not know that 'coal is not good for your soil.' I have a good friend who added Anthracite in rice size several years ago whose garden is the neighborhood best producer. I chose to use rice charcoal which is a step up but he has zero pest issues, the largest sweetest corn I ever had. Therefore, I ask that coal is not good for soil be validated not just a bald statement. Best regards to all.

Here is a link that might be useful: Acres USA

Kimmsr,

I don't think you really made an effort to learn about humate/leonardite. Now, that doesn't really surprise me after reading many of your postings. Try again! Perhaps you can learn something new.

Here is a link that might be useful: About Leonardite

What kind of soils was this research done on?
How much organic matter was in that soil?
If you take a soil that is devoid of any organic matter and add most anything, even coal, you will get some pretty amazing growth for a short time. The same thing happens with peat moss which is in reality young coal.
For long term good, healthy soil you do need to add a lot of once living plant residue, organic matter, coal (once living plant matter) and peat moss however do not count here.

when I post it is because I have seen or read some things contrary to other writers on this forum. The Acres magazine caters to the square mile gardener, farmer, and seems to be very much into organics. Much of the standard practices endorsed on this forum I have applied for the last several years, such as using leaves, ect.
The Humus article(s) in Acres seemed very credible with documentation and test results along with a general humus desciption. I had thought that some would find the articles and archieves interesting. I also think that a good argument was made for the use of Leonardite, clearly not as the only supplement, but in addition to everything else. Leonardite is not available here but Anthracite is. The world may starve to death until all food is grown using only the approved philosophy of some here on this forum.
Best regards to all.

To my understanding (I've read more than a few things about Leonardite) it is not the same as coal that we would burn in a wood stove and perfectly acceptable as a mineral rich/humic acid rich ammendment to any soil. I'm from UT and when I go back I intend to go rock hounding w/ some family that is really into that and bringing back some leonardite as an addition to garden beds. I'd also be on the look out for ancient shale.