Compost Experiment II

I never thought I`d be so interested in a compost pile.

— Elaine · Jun 3, 01:02 AM · #

Same here, Elaine. I am not even sure why I am writing about a compost pile.

Today`s temperature, 06/03, is 35 C. (95 F.)

— Donna Young · Jun 3, 04:38 PM · #

I know why you`re doing it....You`re a homeschooler who just has a huge case of curiosity. You always want to know the `why` of something and I`ve learned that you really like science.

— Elaine · Jun 7, 02:39 PM · #

You are probably right Elaine. Seeing how and if things work is just my nature. Thanks goes to my sweet and dear Mother for being such a patient and understanding woman.

— Donna Young · Jun 7, 05:37 PM · #

Dear Donna,

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
Complete Biogas Handbook

— David House · Oct 12, 07:40 PM · #

Thank you David. If I can, I will try your suggestion next spring. This year, the pile broke down, but it took too long and it did not make the gooey product that I wanted. I puzzle over exactly how to recreate that first pile that made the sought-after okra booster with no help from me. I think your suggestion might be the ticket. Thank you very much.

— Donna Young · Oct 17, 04:18 PM · #