1 lb extractor
2 lb extractor
Stainless steel box
5 lb extract
10 lb extract
400-micron screen
An extract is made by rinsing the microbiology attached to the organic material in the compost. One pound of compost holds over 5 trillion living organisms — spraying water through it rinses those organisms off so they can be applied in the yard, garden, or field.
To produce the extract, add a couple of handfuls (about ½ pound) of mature compost to a gallon of non-chlorinated water in a bucket and stir vigorously — the goal is to dislodge as many microbes as possible from the organic matter.
After mixing, pour the solution through a strainer. A paint screen, such as a 5-gallon mesh bag from a paint store, works well for larger quantities; we use a stainless-steel strainer from a restaurant supply store with a handle, good for up to 2 pounds of compost. Pour clear water through the sieve to extract more microbes until the water runs clear.
The extract can then be added to many gallons of water and applied as a spray, onto leaves or directly onto soil.
Without any further treatment, the compost can be added straight to a growing media or spread onto soil at any desired rate — we've had good success with ½ teaspoon mixed into a gallon of potting mix.
When planting seeds, you can soak them overnight in a bit of water with a teaspoon of compost, then plant. Or add ¼ cup of compost to a couple of gallons of other compost and use this to cover seeds before topping with soil. This is potent — a little goes a long way. An application of 1 pound per acre works out to about 1 ounce per 2,700 square feet.
For our own garden and lawn, we make an extract from a few ounces of compost, add it to a sprayer with liquid fish hydrolysate and water, and spray the grass, bushes, and garden every couple of weeks in the evening — ideally an hour before rain. Avoid applying as a foliar spray during sunshine, as it can damage the biology.
Beneficial microbes from the mature compost can also be applied directly to seeds before they're planted. To inoculate seed, create a slurry with:
Pour one quart of the resulting slurry into a cement mixer or wheelbarrow with about 50 pounds of seed and tumble until the seed is thoroughly coated (roughly 1–2 minutes). Smaller batches can be coated by hand in a 5-gallon bucket.
Air-dry the coated seed on a tarp in the shade, raking occasionally to expose wet areas. It's best to plant the same day, but dried seed can be used up to a couple of weeks later. Large seed can also be planted wet — it flows fine through a planter, and some farmers find wet, undried seed actually sprouts better. Don't add poisons or fertilizer to this mix; if you want amendments in the spray, add them to the tank first.
This example is simplified — our actual inoculant tests higher than this — but it shows the scale involved.
Say there are 1,000 fungi per microgram (the concentration Dr. David Johnson's research points to as beneficial). That's 1 billion fungi per gram, 28 billion per ounce, and 448 billion fungi in a single pound.
Extract that one pound and apply it across one acre (43,560 sq ft) and you get roughly 10 million fungi per square foot. A lab analysis on one of our own early bioreactors actually showed 13 billion fungi per gram — at 1 lb/acre, that works out to about 130 million fungi per square foot.
Emerging research suggests it isn't the fungi or bacteria alone that help — it's the biochemical signaling between them. Depleted soil (poisons, excessive tilling, drought or flooding) loses that communication. More life means more signal.
Compost from the Johnson–Su bioreactor can be used on organic farms. It complies with NOP 5021, effective date July 22, 2011.
Our first two bioreactors used a painter's drop cloth as a cover, which kept the sun off while the pile composted.