One pound of worms can eat 1 pound of manure a day


(Part II of a two-part series.)

SALEM, Ohio – Farmers have too much of it.

Fields have too much of it.

Animals produce too much of it.

“It” is manure, and all the regulations attached to its management add up to big headaches for farmers.

Vermiculture experts are prescribing a hearty dose of earthworms to cure these manure worries.

This remedy eats the manure and excretes a more environmentally friendly waste. The waste is then sold for profit.

It’s a squirmy pill to swallow, but the way farmers do things isn’t working anymore, said Scott Subler, vermiculture expert.

Manure cannot just be dumped on fields due to its high nutrient content and danger to the environment, he said. Heading out with a manure spreader is becoming more difficult due to environmental regulations.

Money, money. This isn’t just a way to manage manure – it’s also a potential money-maker for farmers, Subler said.

The castings, which are more environmentally friendly than the original manure, can be marketed and sold at garden centers as fertilizer.

Subler has worked with livestock producers in Washington, California, New York and British Columbia – helping them integrate dairy manure solids as feedstocks for vermiculture.

Although much of his work has been in large dairy regions, the origins of his vermiculture research began at Ohio State University through funding by the USDA and National Science Foundation.

What is needed. An earthworm manure management system starts by finding spare room in a barn to set up the beds.

Subler recommends beginning in an old barn or parlor that isn’t fully utilized.

The farmer’s next step is to determine how much manure is produced on his or her farm. This number will determine how many worms are needed and, thus, how much bed space is needed.

For example, worms in an 8-foot wide, 120-foot long bed can typically handle a ton of manure per day, Subler said.

A large, full-scale producer, however, would ideally need 16-by-200 feet of bed space, Subler said.

These numbers aren’t concrete, Subler said. The system dimensions can work around the available space in a barn.

Subler estimates that 1 pound of worms can eat 1 pound of manure a day.

Depending on technology and density, up to 2 pounds of worms are in each square foot of worm bed space.

Setting up. After a farmer finds space for the worm beds, next comes installation. The beds are usually made from pallets.

The beds are raised above the floor and there is screen mesh on the floor of the bed.

An automated system pushes the worms’ excrement, better known as castings, through the screen to the floor. The castings are then gathered so they can be marketed.

The automation can be as simple as a winch system or as sophisticated as alley-scraping equipment.

How the manure will be fed to the worms can be as complicated as the farmer wants, Subler said.

The farmer can install a manure spreader on rails above the worms that will spread the manure thin and evenly across the bed.

To make feeding more cost effective, farmers can instead feed with buckets or a skid steer.

Subler said the entire system costs $10,000-$25,000.

Because the system is low technology, Subler said there are ways to save money on setup.

“Farmers normally already have about half the equipment needed,” he said.

“What makes it such a wonderful technology is that it has a straight-forward function and clever farmers can find lots of alternative ways of implementing it,” he said.

Fellow researcher. Clive Edwards, soil ecologist at OSU, has been doing vermiculture research since 1981 and is currently working on a project that uses castings on produce acreage.

Although the results may be premature, Edwards said the castings are having “incredible results” on everything from peppers to strawberries to flowers.

“A small dose seems to have an enormous impact on growth,” Edwards said.

His research project involves using 1-2 tons of castings per acre.

The price of a ton of castings starts at $30 and he said there’s no limit to the high-end price.

Subsidize. Although Subler said farms aren’t using vermiculture as their only source of manure management, he said the profit made from the castings can offset the costs of trucks exporting the rest of the manure.

(You can contact Kristy Hebert at 1-800-837-3419, ext. 23, or by e-mail at

To learn more

Scott Subler       Pacific Garden Company


Clive Edwards

OSU Soil Ecology Dept.


Worm farm information

Lakeside Sales

1535 Celina Road

St. Marys, OH 45885


B&B Worm Farms

Meeker, Okla.


Unco Industries

7802 Old Spring St.

Racine, WI 53406



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