Fungal Compost Carbon to Nitrogen Ratio

1. During the initial phase of aerobic composting, bacteria begin the process of heating and breaking down the pile. Later, the process becomes more fungal as more difficult to digest dried plant material is composted.
2. One important question with any aerated compost is what is the carbon:nitrogen ratio - see chart from University of California Cooperative Extension.
1. One recommendation for Johnson Su (BEAM) compost is 40% green, 40% brown, and 20% manure with half of the brown material being small wood chips.
2. Another is 25% farmyard manure, preferably from cattle or chickens, 25% hay or other dried green material, 25% fresh green material such as grass clippings or forage crop, and 25% chopped corn.
https://farmvillebot.net/2022/05/05/how-to-build-a-johnson-su-bioreactor-to-produce-your-own-on-farm-biology/
3. On the other hand, in a discussion between Jay Young from Young Red Angus farms, David Johnson and Hui-Chun Su, professor Johnson commented that he wasn’t concerned about the carbon-to-nitrogen ratio when making highly fungal BEAM compost.
https://youtu.be/RL7y_qZYGy8
4. In terms of composting bedding pack manure, our experience is that if there isn’t enough nitrogen, the bacteria in the pile won’t proliferate and cause the pile to heat enough to kill pathogens. If there is too much nitrogen, the piles will heat too much due to massive bacterial growth increasing the possibility of causing the piles to go anerobic as the consume all the oxygen and overheat – go above 160F.
3. We estimated a carbon:nitrogen ratio of our bedding pack material that had sat for 6 months to be 10:1 based.
4. We added in wood chips with some dried needles and leaves with a carbon:nitrogen ratio of 400:1 to bring the C:N ratio to about 40:1 – see Cornell website.
5. Carbon:nitrogen ratios are on a weight basis so you’ll need to do some math to figure out how many skid-steer loads of various materials need to be blended t..