"Broad-Spectrum" or "Single Source"

We have often wondered about the difference between the way we compost and the many companies who sell bulk vermicompost. Most, in the USA, are motivated by the need to get rid of a "single source" of waste, such as certain manures. Even the first large vermiculture operation I ever saw was devoted to getting rid of coffee hulls, in Costa Rica.

It was our original intention to develop a way for the typical household to get rid of their organic wastes of all kinds instead of sending them to a landfill. That usually includes a "broad-spectrum" of wastes such as grass clippings, shredded leaves, coffee grounds, kitchen wastes, animal manures, etc. (Not from domestic pets, however, and no meat or dairy wastes that putrefy before decomposing entirely)

Analysis!

Vermicomposts are analyzed in two ways; quantitative and qualitative.

QUANTITATIVE ANALYSIS:

A quantitative analysis is about density. It counts the number of microorganisms in your vermicompost. It doesn't matter if there is only one kind (highly unlikely) but only the number of the total. It seems logical to think that if your compost and vermicompost come from only one source, like coffee hulls, for example, you will have a large number of only a few kinds of microorganisms.

QUALITATIVE ANALYSIS:

A qualitative analysis is about diversity. It counts not only the number, but the variety of microorganisms in your vermicompost. If you have a "broad-spectrum" of organic wastes in your feedstock, it would seem likely that you will also have a wide variety of microorganisms in your end product.
Some composters insist that you need to add some dirt to your compost to provide a "starter" of microorganisms of all species, but we think that unless you are washing off your leaves, etc. first you are getting lots of dirt when you gather your stuff. If you feel it is important, go ahead, but a little is enough.

We believe that there is much in Nature that we don't understand. We know for sure that N-P-K is the tip of the fertilizer iceberg, and we believe that there are things produced for plants by microorganisms that haven't gotten very much publicity, yet. We prefer to think that the more diversity in our feedstock the better.

Why compost organic waste first?

In a small worm bin you can add your household waste directly to the worm bin, but in a mid-scale vermicompost system we have found it to be advantageous to combine the materials in compost bins first. Our objective is to process the compost into WORM FOOD. Two bins are better than one, and they must be at least 3'x 3'.

We keep some grass clippings or shredded leaves on hand to cover any fresh household waste or fresh manure. That discourages flies and vermin. We avoid sticks, branches and stalks, and the leaves and grass are chopped fine with a lawn mower. Large leaves will mat together and slow the process of decomposition. (No domestic pet manure or meats or dairy wastes are allowed).


Our compost goes anaerobic immediately and we encourage it by keeping it damp. Our leaves, grass clippings, and household wastes tend to begin as layers, sandwiched between the coffee grounds and filters from the local coffee shop. When we use a pitchfork to toss the contents of one bin into another the materials get mixed better.



After the compost has been tossed once and has heated again, we screen the worm food through a 1/2" screen. This gives us a uniform texture. The people down at the coffee shop tend to throw bottle caps, etc. into the pails, so the screening also gives us a chance to remove the inorganic waste. Sticks, stalks, and big lumps go back through the compost bins for another cycle.
 Since composting worms live in the top 6"-8" of forest litter, each VermiChester tray represents about 3 square feet of forest. By stacking them up and keeping them full, the worms can travel in every direction just as in nature. One full stack of 5 would be like 15 square feet of forest space. I thought that the vermiculture manager at La Palmichal told me that he doesn't allow their litter to get deeper than 20" deep, but in retrospect he must have said 20cm. He wouldn't normally use inches.That would be about 10", which is why I prefer the shallow bread trays.

I designed the VermiChester system with the cloud forest rainfall in mind. Even a steady rainy season won't harm the system. It merely washes out "VermiJuice" and leaves worms and undigested organic waste behind. During the dry season, or indoors, the system should constantly drip into a bucket. When it stops dripping, your moisture content has reduced to under 50% which is too dry. The ideal is 70% moisture.

Converting Organic Waste into VermiCompost With Worms

I learned about vermiculture backwards. I visited a coffee processing plant in Palmichal, near Tabarcia, in Costa Rica, and witnessed a large industrial vermiculture operation. They were composting their waste coffee hulls with more redworms than I even imagined could exist. They were using a windrowing system that is now the standard of the large-scale industry. They had learned most of what they were doing from a scientist from Pinar del Rio, in Cuba. I hope you have time to watch the slide show. My aroused curiosity started a search that seemed to always end up at very large or very small systems. There seemed to be a need for a medium-sized system.

I have provided a link to NCSU, where Rhonda Sherman has established an international resource for large-scale vermiculture, as practiced throughout the world.

You can't go wrong by reading the book "Worms Eat My Garbage", by the late Mary Appelhof, if you want a small system. I bought my first pound of Eisenia fetida from her.

What I have developed is a medium-sized system.

A VermiChester system is a simple arrangement of stackable bakery trays on a raised base. The trays are completely filled with composting worms and screened composted organic waste.

Water is added until the system drips dissolved worm castings into a pail. The percolation of the castings exposes the slower decomposing materials to a longer period of digestion. The drippings are siphoned to remove large sediment, bottled and labeled VermiJuice for sale at Farmer's Markets, etc. Scroll down for a post about "Compost Tea" The liquid can be diluted as much as 8 times for plant feeding and irrigation. Some users have seen a remarkable reduction in plant pests as well as increased growth of healthy plants.
 In time, the contents become VermiCompost.

HARVESTING:

Rotation of the trays allows the bottom tray to be removed for harvesting. It has been there the longest.
Remove each tray from the stack, and stack it on the last tray removed.
Set the bottom tray aside.
Re-stack the trays.  The tray that was next to the bottom is now the bottom tray. Stirring of the contents during the rotation loosens the contents to ensure full trays and more even access by the worms.
Water the stack until it drips, again. Do not wet the tray that was on the bottom.
Place the old bottom tray on the top of the stack to dry. Typically, since worms prefer fresh worm food to living in their own excrement, there won't be a lot of worms in this tray. Those will gravitate to the lower wet trays, and you will have very few adult worms in this tray.
If you are not in a hurry, put some fresh "Food Balls" on the top tray. There are cocoons that will hatch and the baby worms may have time to crawl up into them. You can put those new worms in your farm.

Now is the time to read about the labor-saving VermiHarvester.

While it would appear that the purpose is to restore humus to depleted soils, the big picture involves eliminating organic waste from landfills, etc.

In Costa Rica, small farmers with 6, or more, pigs, collect the manure in a modified septic tank with a plastic "bladder" cover. The manure produces methane which is piped into the kitchen for cooking. The digester drains out of the bottom. Vermicomposting the spent effluent would increase the value at least 8 times. The potential application for CAFOs in the USA should be obvious. That would require a much larger system.

VermiHarvesting

You probably know how to use bright lighting to inspire your worms to burrow down into the deeper compost. If your system is inside, this will speed them along. Outside the sun will work for you.


Fluffing up the material in the top tray annoys the worms a bit and inspires them to burrow down quicker. I come back the next day, or longer, when the top tray is drier. By then, many of the worms will have left the dry top tray for a wetter and darker neighborhood.

When the worms have completed their work, it is your turn. To preserve your herd and remove a nice uniform vermicompost from the system you need to harvest your product. This can be a tedious and boring task.

You could just build a frame and use 1/8" wire mesh hardware cloth, and shake the contents of the tray into a wheelbarrow.or you could, ... Build an inexpensive VermiHarvester.  

Click on the tab above for details.