How to make a Johnson Su Bioreactor out of a chemical tote with Cory Miller from Grass Valley Farm

Wow! When we made "How to compost on a large scale' we had no idea it would spread so far! It brings us so much joy to hear from you and know that our film is inspiring you to try out natural alternatives to chemical fertiliser.

So here is the follow-up. How to make your own bioreactor with a twist. We've taken an old chemical tote and converted it into a bioreactor so that you can make your own fungal-dominant biocomplete compost. This reactor is inspired by the science and method of David and Hui Chuin Johnson but with Cory's ratio, recipe and construction methods.

There are no exact ratios when making a Johnson Su bioreactor. Cory likes to use 10% high nitrogen, 60% wood and brown materials and 30% green materials. The aim of the game is a diverse compost pile with higher carbon for a highly fungal compost pile. Ours is 9 months in and has mushrooms growing on it, so it looks like it’s working! We’ll be getting the finished compost under the microscope in January. I’ll also be sharing a short video on irrigating the pile and how to make a compost extract in 5 5-gallon bucket. So hit subscribe and stay tuned!

For this video, we used:

4 tubes with 1-inch holes cut in half to make 6 aerator cylinders.

I don’t recommend using weed fabric like used in this video. It split already! Dr Johnson recommends 5.2 landscaping fabric for proper air infiltration, maintaining proper moisture content, and durability to withstand a 12-month maturation period and to be reused again.

Concrete mixing tub for mixing materials: https://www.homedepot.com/p/Black-Lar...

Cable ties: https://www.amazon.com/Superun-selflo...

We got our tote from a hand sanitiser company in downtown LA. Many farms will have these, as synthetic farm chemicals also come in these totes. Let's put them to better use!

For this video, we used horse manure, as we have so much for it. It’s better to work with manure from animals that aren’t vaccinated; this can affect the microbiology of the manure and therefore the microbiology in your compost pile. You can use any animal waste- chicken, cow manure etc. If you use horse manure break up the apples. Make sure your woody material is less than 3/8, so that it breaks down within the 12-month composting period.

Options for nitrogen: mushroom farm wastes, spent grains, food waste, green waste from the garden and grass cutting, animal manure, seaweed, and weeds without seeds.

Options for carbon: dead leaves, wood chips, cleared brush, shredded carbon, old hay bales, corn hobs and husks, coffee grounds, wood chips

A fungal-dominated compost pile can be beneficial for several reasons:

* Nutrient Cycling: Fungi are crucial in breaking down complex organic matter, such as woody materials and lignin, into simpler compounds. This contributes to efficient nutrient cycling in the compost, making these nutrients more accessible to plants when the compost is used as a soil amendment.
* Soil Structure Improvement: Fungi produce a network of fine threads called mycelium, which can help bind soil particles together, improving soil structure and aeration. This can lead to better water retention and root penetration in garden soil.
* Disease Suppression: Some fungi in compost can suppress harmful pathogens and pests, acting as a natural biocontrol mechanism. This can reduce the risk of plant diseases in your garden.
* Carbon Sequestration: Fungi can help sequester carbon in the form of stable organic matter in the soil. This contributes to carbon storage and mitigates climate change by reducing atmospheric CO2 levels.
* Decomposition of Tough Materials: Fungi are effective at breaking down tough, lignin-rich materials like leaves, straw, and woody debris that bacteria may struggle to decompose efficiently.
* Enhanced Soil Microbial Diversity: A fungal-dominated compost pile can contribute to a diverse microbial community in the soil, which is generally beneficial for overall soil health and plant growth.

I hope this video inspires you to make your own bioreactor. Let’s learn together as we find better ways of growing and farming that don’t cost us the Earth. I value your feedback and we are here to help! So reach out with any questions, both of us are available by email. Cory welcomes visitors at his farm in Montana and is always happy to chat on the phone.

We love to hear stories and see pictures of people trying these methods, so please tag us if you share photos or videos. @amy_oftheplants and @grassvalleyfarms