Johnson-Su Bioreactor

The compost produced in the Johnson-Su composting bioreactor provides nutrients and, more importantly, results in a microbially diverse and fungal-dominant soil microbiome that can be applied at concentrations as low as 1 kg/hectare, a concentration at which it operates more as a microbial inoculation for plant roots than as a soil amendment. In other words, the inoculant introduces beneficial microbes at the new roots like a baker introduces yeast to bread dough. The increased presence of fungi appears to be a key indicator for soil life, both in the terra preta soils of the Amazon and the inoculant produced in the Johnson-Su bioreactor.


What makes the Johnson-Su Bioreactor Better?

  1. No need for turning - static is best!
  2. Airflow within 6 to 12 inches throughout the bioreactor
  3. No rotten smells, no flies
  4. Only about $100 worth of materials
  5. Revives soils by creating a fungal-dominant and diverse soil community after a year of implementation.
  6. A little goes a long way (2 pounds/acre)
  7. Increases crop yield
  8. Creates healthier nutrient-rich produce
Detailed Instructions

Getting Started


  1. Landscape Cloth (woven, minimum 5 oz.): Piece One: 13’ x 6’, Piece Two: 6’ x 6’, Piece Three: 6’ x 6’
  2. One standard, sturdy shipping pallet with dimensions of approximately 40” x 48”
  3. Wire mesh (6” x 6” x 10-gauge wire), used to create a 5’ x 12’ 6” supporting wire cage. This type of wire mesh is normally used for reinforcing concrete. Be sure to use wire mesh (livestock fence or other similar wire fence products have insufficient vertical strength to hold the cage in position as you fill it).
  4. Four 10’ lengths of perforated, bell-end, 4” septic system drain field piping
  5. PVC glue
  6. Tie wire (normally used to tie rebar together)
  7. Approximately 13’ of ½” landscape water hose for the drip irrigation system
  8. Optional: A rebar jig to hold the drain field pipes in place as you fill the Johnson-Su bioreactor. If you have helpers or if you are willing to adjust the pipes as you fill the bioreactor, you will not need the jig.


  1. Small bolt cutters or heavy pliers for cutting the wire re-mesh
  2. Linesman’s pliers to cut and tie the tie wire for assembling the cage
  3. Circular saw
  4. Jigsaw for cutting holes in the pallet
  5. Scissors or utility knife for cutting the landscape cloth
  6. Tape measure
  7. Pen or pencil to mark places that will be cut

Detailed Instructions

The PDF below contains detailed instructions and procedures related to the Johnson-Su bioreactor. It has been prepared by David Johnson and Patrick DeSimio on June 28, 2017.

  1. Go to page 9 to see detailed instructions on how to make the Johnson-Su bioreactor.
  2. Go to page 12 to find detailed instructions on how to fill the Johnson-Su bioreactor.