Johnson-Su Bioreactor fungal based composting system

Most soils, especially in urban or disturbed areas, lack fungal-based microbes due to compaction, tilling, and chemical use. Fungi play a crucial role in building soil structure, cycling nutrients, and forming symbiotic relationships with plants—benefits that bacteria alone can't provide. Forests are the perfect example of this balanced relationship. 

The Johnson-Su bioreactor is a low-maintenance composting system that produces microbially rich, fungal-based compost as opposed to traditional composting systems that are bacteria dominant. Developed by Dr. David Johnson and Hui-Chun Su, it uses a passive, aerobic (high oxygen)  method that allows the beneficial fungi to grow. 

Made from a recycled IBC container, with vertical aeration tubes, the bioreactor breaks down organic material slowly over 9–12 months. The base has holes in it and  the cage is lined with shade cloth to allow as much air as possible to pass through. As the system relies on oxygen, it must be carbon-based, meaning it should be 90% carbon (brown things like straw, woodchips, dried leaves, paper) and only 10% nitrogen (greens) and must be watered regularly to allow the microbes to grow. Having an automatic irrigation system setup can be very helpful. The end result is a fine, earthy compost often called "compost inoculant" which is packed full of beneficial fungi. Only very small amounts are needed to improve plant health, increase soil carbon, and promote long-term fertility by either mixing directly into soil, or steeping it in water as a compost tea.