AyatollahGondola
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Artificial compost heat

Hi all,

I'm new here. I would like to ask if anyone has knowledge or experience with using artificially induced heat to speed up composting. I was basically thinking that using solar heat to raise the temperature to a more desirable level for longer periods than what the natural reaction produces after the prime drivers have depleted.

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JC's Garden
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Location: Moultrie, GA Planting Zone 8, Sunset Zone 31

In zone 8 all I have to do is add some manure and the temp comes back up.
I have used a black plastic cover to help it heat up but you can't leave it on, the pile needs oxygen to break down properly.
Where are you located? If you will fill out your profile, people can tell you what works best in your area.
Good luck and welcome to the forum.

tomc
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Screening, and not more decomp will make for a uniform pretty compost. if its heated, and shrunk, and then cooled, its ready to go.

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digitS'
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I may have some of the same limits you have. But, I'm just guessing ...

I get everything off a couple of my gardens before winter. Plants that were hardy enough to not be killed in the first fall frosts are buried under about 8" of soil in October. I can dig into that bed in March and still find green plants ..!

Nothing much decomposes no matter where it is until July -- then, it nearly bursts into flames! Two months, everything shuts down again.

Moisture is a real limiting factor along with the lack of ambient warmth. That's here, where we may get zero rain during some of the summer months. I find that as much soil-contact as possible is important. Of course, I have to run sprinklers on the compost about once a week.

Another important element is patience (unless it's mid-summer ;)). I can carefully build a fairly conventional compost pile and simply leave it alone ~ unturned ~ for 18 to 24 months and it will be pretty good compost. I used to do that but I may be a little more impatient now, in my olde age ...

:) Steve

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rainbowgardener
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They do say having your compost pile in full sun helps speed it up, due to the warmth. But if you did that, it would be even more important about the water, because it will dry out faster. If it is dry enough to water my garden, I water the compost pile also. If it dries out, it quits working.

AyatollahGondola
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Thanks for the replies,

the history here is this:

I have a decent sized compost bin probably 2 yards or more on each side. The slats are staggered and double layered, so there is good air supply. The mixture seems good. I also put an insulated blanket on the top to hold in heat an moisture. The temp has run the cycle, getting up to as high as 153 degrees for some days, and then I had to add some water when it dropped. the temp resumed, albeit a bit lower peak each time. There has been good decomposition, and some fungus here and there. A lot of bugs. But....there's still a lot of larger twigs and tubers that I thought might break down further if artificial heat was introduced as opposed to adding new green material. I have access to some triple pane windows and some heat exchangers, and wondered if this was worth building a solar heater for, or an exercise in futility. I'm in Sacramento California. Our lows at night have been 40's, and highs for the days in the 60's

AyatollahGondola
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digitS'
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Looks like a good set-up, AyatollahGondola.

Being a lack-a-daisy, I don't use a thermometer but I'm surprised that 153°f isn't what you are hoping for. That's medium-rare for red meat, according to the USDA ... ;).

Could it just be a turning problem for the twigs and tubers? Of course, I have twigs that make it through several compostings.

Steve

AyatollahGondola
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digitS' wrote:Looks like a good set-up, AyatollahGondola.

Being a lack-a-daisy, I don't use a thermometer but I'm surprised that 153°f isn't what you are hoping for. That's medium-rare for red meat, according to the USDA ... ;).

Could it just be a turning problem for the twigs and tubers? Of course, I have twigs that make it through several compostings.

Steve
Yeah, that was peak. the temps I'm obtaining are in the 120 range or less today. I was trying to find a way to do more composting with fewer cycles

tomc
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Very chunky wood and lignin rich leaves are tougher than Marley's ghost. Those shadows of garden and woods past only need removal from planters or seedling flats. In your (OK my) garden proper I would not bother to remove their twiggyness. I don't bother to smash up oyster or clam shells either.

It is possible to buy nitrogen containing material like blood-meal or urea. They have a very high nitrogen content, which will spur compost to heat up again. With urea you are near to going off the organic method reservation.

toxcrusadr
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Keep in mind that compost continues to degrade even after it cools and appears 'finished'. You want to use it fairly soon. By composting the whole pile longer or hotter, the parts that were ready to use first may shrink while you're waiting for the big chunks to decompose.

Half-composted chunks can finish breaking down in the soil if you're not too fussy about how uniform and fine the soil is in the bed. Or, you can chop those better in the first place, or recycle the chunks back into a new pile. That also helps inoculate fresh materials with all those microbes.



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