#117 - Step-By-Step Active Composting - Day 8

I checked the compost piles today and I noticed that Pile #1 is staying at a good temperature of about 140 degrees so I do not want to disturb it. At 140 degrees it is actively composting without being so hot that it risks killing off the beneficial microbes. So I am not going to turn that pile today.

Pile #2 on the other hand is still running hot at just over 160 degrees so I need to cool it down just a bit. Adding the carbon to the pile yesterday in the form of the shredded cardboard did help to bring the temperature down a coupe degrees, but it did not bring it down enough.

For me to bring the temperature down to the 140-150 degree range where I want it to stay at using the addition of carbon I would have to add a lot more shredded cardboard which I do not want to do just yet. Cardboard has a carbon to nitrogen ratio of about 350:1 which is why I used shredded cardboard to bring up the carbon percentage in the pile. One reason the pile is running so hot is because it has a high nitrogen content from the grass clippings.

One other thing that has the ability, at least temporarily to bring the temperature down is turning the pile over to reintroduce oxygen to the pile. If you will remember yesterday the pile was a little wetter than I would like for it to be. Too much moisture means there is less oxygen in the pile because the water fills up the tiny spaces where the oxygen should be inside the pile. Too much of wither means not enough of the other, either way it is not good for a compost pile.

I decided to try turning pile #2 today to drop the temperature down and dry it out just a little more to see if that will help the temperature stabilize. Turning the pile is a double-edged sword though as it is also used to heat a pile up that has cooled down if it cooled down from lack of oxygen. Turning a pile can go either way with the temperature so I am going to have to watch it closely.

At least for now turning the pile over has dropped the temperature of the pile down to 130 degrees. Let's see how long it takes for it to climb back up again.

I still want to add carbon to the pile to regulate the temperature, but I need something that has a lot higher carbon to nitrogen ratio so that I am not making the pile too large which will also contribute to more heat production in the same way that putting on a thick coat in the winter time helps you to stay warm. The larger the pile gets, the more insulation the pile has to retain heat generated by the decomposition inside it.

I want to try to stay at around a 3 cubic foot pile size, so if I add another 2 or 3 cubic feet of cardboard to slow the pile down and cool it off I would be well over my 3 cubic foot pile size limit, I would be doubling the size of the pile.

There is a product that I can add to the compost pile that will significantly increase the carbon to nitrogen ratio without increasing the size of the pile dramatically, which is sawdust. Sawdust has about a 500:1 carbon to nitrogen ratio, which is quite a bit higher than shredded cardboard. Of the items that I can easily add into a home composting pile, sawdust has the highest carbon to nitrogen ratio.

Unfortunately I do not have any sawdust laying around and there is not a sawmill anywhere near my location. I have ordered a total of 35 pounds of sawdust from the mainland but shipping on it is very slow and it won't be here for a few more days. I will not need anywhere near that much of it for this compost pile, but I want to make sure I have it in stock for future piles.

I did not realize until the other day that I was completely out. I ordered 25 pounds of fine sifted sawdust and 10 pounds of medium sawdust with wood shavings.

The finer the sawdust the better it is for temperature control of the pile and the faster it breaks down and decomposes.

The medium sawdust and wood shavings are good for moisture retention and creating air spaces in the compost pile, they are also good for helping the compost pile to create a loamy humus that we need for our finished compost ready to be used in the garden.

You never want to add wood chips or mulch to an active compost pile because they take several years to decompose and are not able to be broken down quickly enough in this type of a composting system. They are more suitable to a cold compost pile which will not be used for a few years. For an active composting system like this, never go any larger than medium sawdust and wood shavings.

I will be using a combination of both throughout the lifespan of the compost pile. Once the sawdust comes in I will add about a pound of the fine sawdust to the pile which should take care of the overheating issues and slow the pile down a little.