The temperature readings in the pile have been puzzling me. Today, I’ll describe how I have tried to improve matters.
While doing the morning chores, I run the air compressor to aerate the biomeiler pile. I expected that the internal temperature would increase after the recent upgrade to the aeration system. There should now be a significantly greater amount of fresh air added to the pile each morning. However, instead of increasing, the internal temperatures have decreased. There have been similar cooling events in the past, but they had contemporaneous factors I thought explained the changes. Now, though, I think the aeration is the cause of the cooling.
My two hypotheses are: 1) that the extra aeration could be drying the pile and the temperature drops until moisture migrates from other areas to the aerated areas; and, 2) that there aren’t enough aerobic bacteria in the pile to make use of the extra oxygen and the anaerobic bacteria are harmed by it. The pile is made of recently-used chicken bedding and this year’s yard rakings mixed in with the material from the previous biomeiler piles. The previous biomeilers were all anaerobic. So, the aerobic bacteria in this year’s biomeiler are likely not the majority population.
We are currently having a spell of ridiculously warm weather. Sadly, a mid-winter rain storm is an increasingly-common event, here. The snow layer on top of the pile had greatly diminished in volume and removing the remainder would not be too difficult in the warm weather. So, yesterday, I sprang into action and uncovered the top of the biomeiler to attempt an improvement.
After uncovering the pile, my first observation was that there was a great deal of frost and ice under the Reflectix sheets. This observation supports my hypothesis that the aeration may be removing too much moisture from the pile. Next, I observed that the surface has sunk in two large areas. In the picture, I included a glove for scale.
The depressed area is roughly 2’x3’, and about 5” deep at the deepest point. It is normal for compost to settle unevenly, but that is more localized than expected. There is a similar depression on the far side of the pile. I interpret these depressions as an indication that the composting action is not uniform throughout the pile.
Fresh chicken manure contains aerobic bacteria and I know where I can get plenty for free. So, I mixed 5 gallons of fresh chicken manure with 5 gallons of warm water and stirred it into a slurry. The slurry was poured in the center of the pile. I mixed another batch and poured it in adjacent areas. The two batches covered the top of the inner core. I followed the slurry with another 5 gallons of warm water to help wash the bacteria deeper into the inner core. Sorry, no close-ups.
Today, I mixed two more batches of slurry and poured them over the top of the outer core. I followed the slurry with 10 gallons of warm water. After that, I repositioned the Reflectix insulation and tarp and put blocks of snow on top of them to hold everything down until fresh snow arrives. The forecast calls for temperatures to drop to -1F tonight and to the -30s in the next few days. There should be snow falling if the air cools off that much.
The goal of the treatment was to increase the moisture level and the population of aerobic bacteria so that the aeration of the pile leads to improved composting action. If it works, I hope to see increased temperatures in the inner and outer cores in the next few days. Fingers crossed.
It’s a good thing you are heating your coop with this experimental type of heat – and not your house! This year’s best efforts aren’t rewarding your personal energy investment very well!
Are you already planning a different set up within the biomeiler next year?