If Mother Nature's practices work so well and there is no such thing as hot composting in the natural scheme of things, does a hot compost pile produce a superior product or an inferior one? Are there benefits (other than speed) to be derived from spending the time and energy required to get the piles to heat up that outweigh the possible loss of microbes and nutrients caused by the heat generated? Does a hot pile produce a good quality humus (which is what we're trying to achieve), equal to what occurs naturally? Does a cold "pile" mimic the layer of naturally decaying vegetation or is it actually an artificial method in itself that loses something in the process? Would our gardens be better off if we just layered the materials on top, like it occurs in nature? (I'm not talking about deep layers such as in lasagna gardening, but similar to sheet composting which is what we practiced on the farm when I was young.)

This is what comes from having a bit of time to contemplate my gardening practices! LOL

Sandy

I'm not sure that assumption will hold up. ;) It's the "if a tree falls in the forest and no one is there to hear does it make a sound" analogy.

Here in the thick woods one can hike for just a short distance and discover many of Mother Nature's compost piles. But we have no way of knowing if they were ever "hot" piles or not. Perhaps the C/N ratio was good, the rain came, and wildlife stirred up the pile to use it's warmth.

Are there benefits (other than speed) to be derived from spending the time and energy required to get the piles to heat up that outweigh the possible loss of microbes and nutrients caused by the heat generated?

Yes, pathogen and weed seed kill.

Don't get me wrong. I am not critical of cold composting, do it myself in some cases. For me, it all depends on the pile components as to whether I want it to cook or not. If it is manured compost, I definitely want it to cook. If it is heavily made up of weeds, I want it to cook. If it has diseased garden plants in it, I want it to cook. But if it is primarily fall leaves or straw, wood chips, hay and kitchen scraps and coffee grounds, it can cold compost with no problems AFAIC.

Dave

I run cold piles mostly and, since I'm a mulcher, I don't worry about weeds showing up from seeds that might survive the cold process.

Sandy

I cold compost because I am too lazy (or I have better things to do with time)...and plenty of space.

I have thought about taking some of the partially finished compost from my cold pile and putting it in a tumbler to speed it up a bit. But it was just a passing thought.

I think some plants (woodland types, not necessarily veggie garden types) would benefit from fungal dominant organic matter.

Just like Cornell says.

I end up with a decent product.

Cause that's just the way I do it.

Lloyd

I'd like to know if there has been a study done on the subject but I doubt it makes a huge difference to plants. Altho I have very few problems with disease in my garden so maybe...

Studies have shown that compost produced at these temperatures has less ability to suppress diseases in the soil since these temperatures may kill some of the beneficial bacteria necessary to suppress disease.

Person "B" also builds his pile, heats it up to 150 degrees, turns it until ambient temperature but also lets it mature (cure) for an extended time (2-3 months). "B" then uses this compost in their garden.

Person "C" builds a pile, never gets above 110 degrees, doesn't spend a lot of effort turning it or otherwise managing it. After a year they use this material in their garden.

Person "D" takes all the feedstocks and spreads them over her garden in the fall and plants in the spring.

So whose compost is 'better' and 'better' for what? Did persons A and B both practice "hot composting" and will their product be the same?

Like Sandy, I have also contemplated this subject looking for "the answer". I can find lots of information on line but the vast majority just say "studies find" and any real studies I do find are too complicated or focused to be of any use to me (which means I'm too stupid to understand them).

IMO, there are just too many variables, complications and permutations for any definitive answers. (And I tend to not take too seriously those people that profess that they 'know').

Lloyd

Kimmsr, do you know of any studies that have compared the two kinds in actual growing conditions? I'd be interested in reading them if you do. The article from the Dept. of Ag. that anubis cited states the disease supression as if it is fact but I haven't found any studies to back that up.

Sometimes I'm amazed that we grow anything successfully. Between the vagaries of the weather, insect appetites, disease infestations, and poor soils, it's almost a miracle that things grow as well as they do. I'm constantly learning that something I thought was a good idea might not be the best way of doing things. This compost question is just one of the things I think about in my garden. Maybe I'm just looking for justification for being a lazy composter and keeping my cold piles going.

Sandy

I am proudly counted among what has come to be known as an "SOS" (Student of Solomon). What I have learned from being a "SOS" is that all compost is not created equal. From the book "Organic Gardener’s Composting" by Steve Solomon comes the following:

"Many people, including writers of garden books, mistakenly think that the composting ends when the pile cools and the material no longer resembles what made up the heap. This is not true. As long as a compost heap is kept moist and is turned occasionally, it will continue to decompose. "Curing" or "ripening" are terms used to describe what occurs once heating is over."

Further explaining:

"Rhizobia are not capable of being active in compost piles, but another class of microbes is. Called azobacteria, these free-living soil dwellers also make nitrate nitrogen. Their contribution is not potentially as great as rhizobia, but no special provision must be made to encourage azobacteria other than maintaining a decent level of humus for them to eat… Once a compost heap has cooled, azobacteria will proliferate and begin to manufacture significant amounts of nitrates, steadily lowering the C/N. And carbon never stops being digested, further dropping the C/N. The rapid phase of composting may be over in a few months, but ripening can be allowed to go on for many more months if necessary." (See link below: "Curing the Heap").

Those who claim compost is "finished" whenever his or her logic states, should honor the community by explaining exactly where "humus" comes from. It indeed would be of great help if said explanation is of a better caliber than past circle talk that has been offered when such a request manifests.

A mixture of both hot and cold composting will provide good quality compost; the deciding factor will forever remain "time". In a pile (cold or hot), in a tumbler, within a lasagna bed, sheet composting, Interbay mulching, or closed anaerobic composting will all provide the same thing, compost; same in fact which too will continue to decompose until humus is achieved. IMO, the time spent working towards whatever goal the gardener/farmer is striving for is the most important part; satisfaction from activity that provides physical participation, gratification for the eyes watching the process, and the delight of reaping what one has sowed is what this is all about to me…

Blutranes

Thanks, Bob

Happy Easter!

Chapter One

At the top and bottom there are links to the next chapter, Like BT, I also like Solomons' ideas and concepts. Easy to read, logical and understandable.

Lloyd

Like many an apartment dweller, in my twenties I raised tropical fish and grew house plants just to have some life around. The plants did fine; I guess I've always had a green thumb. But growing tired of dying fish and bacterial blooms clouding the water, I reasoned that none of the fish I had seen in nature were diseased and their water was usually quite clear. Perhaps the problem was that my aquarium had an overly simplified ecology and my fish were being fed processed, dead food when in nature the ecology was highly complex and the fish were eating living things. So I bravely attempted the most radical thing I could think of; I went to the country, found a small pond and from it brought home a quart of bottom muck and pond water that I dumped into my own aquarium. Instead of introducing countless diseases and wiping out my fish, I actually had introduced countless living things that began multiplying rapidly. The water soon became crystal clear. Soon the fish were refusing to eat the scientifically formulated food flakes I was supplying. The profuse variety of little critters now living in the tank's gravel ate it instead. The fish ate the critters and became perfectly healthy.

The bottom muck of the ponds is natural habitat for archae-bacterias such as purple bacteria. They decompose organic sediments naturally falling on the bottom of lakes, seas, ponds without toxins. Purple bacteria Rhodobacter sphaeroides is an important part of microbial inoculant EM that is used for cleaning drain channels of fish industry full of organic wastes.
One of the most important part of ancient (4000 ago) method of making anaerobic compost in China was also an addition of the muck (to organics ) from the bottom of water channels all around the rice fields. It makes sense.

"I have to disagree about needing large volume to get a hot pile"

You don’t need a big pile to get heat. I can dump a muck bucket full of HM on the ground to use for the next pile, and, in a couple of weeks using this to build the next pile, you can see that it heated up pretty good, evidenced by the grey ash colored material in the middle of the pile.

However, the ratio of this material vs the outside layer that had no action is very small, thus not having much ‘composted’ stuff to do anything with. The 3x3x3 is a good optimum size for home composters that do everything with rake, shovel and fork. You get the mass for good temps and good porosity, and a good amount of compost when it’s done.

Being an older person, I can’t comfortably turn a 3x3x3 at once, I use a lot of 24" chicken wire by 3’ diam., heaped up some. I get good temps and after 2-3 turns it’s in pretty good shape to use in garden. My 1st 3 piles were pretty much ready to go in 6 weeks. I put a box inside the mesh bin when I turn, into which I put the outside layer, then pull the box out after surrounding it with the rest, thus ensuring all material spends time inside the pile.

LOL, belindach! Sometimes I think I'm in the same boat.

Very interesting thread. Thank you, everyone!

Dee