Compost Experiment II
Yesterday the compost pile had cooled to 38 ºC (100 ºF). That is not hot enough for this experiment. I suspect that the grass clippings are too dry. This afternoon, I removed the cover. It seemed that only the damp parts of the pile were heating and the outer parts were indeed too dry. While out there, I measured the temperature and it was lower than yesterday’s reading.
While the pile was uncovered, I noticed that it was steamy toward the middle and it had a fermented odor which, unfortunately, drew flies that bite. Anyway, I set out to dampen the grass clippings and that was like tossing a 15 cubit foot salad. To do it, I shifted the pile over, watering the clippings as I moved them. Then I dug a new trench around it and recovered it with plastic, and buried the edges in the trench.
Two pictures:
Taking the pile’s temperature
The watered and shifted pile recovered
The problem with compost dampness is that neither too little water nor too much water is optimal for the fast bacterial breakdown.
In a few days, I will have to uncover the compost pile to check on it, and possibly, to turn it.
We’ll see what happens next.
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Today`s temperature, 06/03, is 35 C. (95 F.)
Since you are doing this experiment (which was mentioned on an e-list to which I subscribe), perhaps a bit of science might help. In your initial post about this subject, you said "A name for this type of composting is anaerobic. Apparently, the conditions were right for a high heat inside the grass clipping pile. A part of the pile, the middle, was partly closed off to oxidation and produced a lot of heat."
Two things. First, the way you describe it, the middle of the pile was almost certainly anaerobic, but anaerobic composting, according to everything I have been able to find out about the subject, cannot produce high heat, because without oxygen (that`s what "anaerobic" means), the microbes must use a different kind of metabolism which is very inefficient; in other words, it does not generate much energy, so there`s not much heat. The second thing is that oxidation, which is a chemical term, perhaps confusingly can occur where there is no oxygen. (You can look it up: Wikipedia on oxidation.)
What it seems to me was happening was that the center of the pile went anaerobic, while the outside of the pile stayed aerated, and so it was the outside of the pile that was generating the heat, and heating up the inside of the pile. If that`s correct, then covering the pile with plastic is precisely what is causing it to get colder. So what you may want to try is to put some of the grass in a large plastic bag (where it will certainly go anaerobic), and surround it with a hot-- aerobic-- compost pile. The stuff in the plastic bag would eventually become your sought-after okra booster.
If you try this, I would be very interested in what you find out-- I am not likely to try it myself, since my wife does the mowing, and we do not have a grass catcher...
d.
David House
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