Tom Herlihy, RT Solutions, runs the largest agricultural vermicomposting facility in North America. Here are my takeaways from his talk:
Company’s mantra for production: That it be consistent uniform and repeatable. Note: they produce compost as opposed to worms.
Note related to earlier discussions at conference: he says there is no such thing as a “pure casting”. Worms alter availability of nutrients. What you put in affects what comes out so you have to know your own material. If you take a consistent feedstock, you can have a consistent product. (His feedstock is dairy farm cow manure from animals that are fed consistent feed.) The cows are not certified organic but the compost product is organic because it went through a hot composting process.
Demoisturize and compost thermophilically. Vermicompost in flow through digesters (feed from top, harvest from bottom). Beds are fairly deep so the cocoons aren’t harvested and to allow for mesophilic composting. They harvest from the bottom in 45 days because the cocoons will have hatched before then. Note: Worms breed at a lower level if you over-water because they follow the moisture.
Animal husbandry of worms is most critical. If you treat them like garbage…
In the compost beds: look for cocoons and reproduction
They do extensive screening and ship in huge bags. They also do small packaging and liquid extracts. (Their extract is a non-aerated dissolved worm compost.
About vermicompost extract: it is a stable plant growth product.
If you want to sell extract or tea, you should know its solubility and test it — these tests can be inexpensive.
They don’t use municipal water to create an extract or tea or in vermicomposting because it contains chlorine
You can store vermicompost 18 months
He has done lots of research including work with Allison Jack on suppression of pythium (damping off) Vermicompost-treated seeds are shown to repel pythium. Results are seen in plants seen with seeds exposed to vermicompost for just a couple of hours. When vermicompost was heated to kill the microbes, the suppression of pythium was lost.
Plant growth research: they get results with 3-12% vermicompost. This depends on the nutrient density of the particular compost.
He advises that you use vermicompost next to the plant — not broadcast on a big field. An extract may be more appropriate to spray on a field especially for repeat applications.
He gave another example of successful results — top-dressing a golf course with nine parts sand, one part vermicompost.