Vermiculture in the Southern and Eastern United States

Vermicycle Organics, Inc.

Vermicycle Organics, working with group of hog producers, is constructing a series of greenhouses to accommodate more waste. Each 220-foot (67m) by 35-foot (10.7m) greenhouse provides shelter for three earthworm beds. On one site alone a total of 16 greenhouses are scheduled to process about 7,500 tons (6,806 metric tons) of manure per year (Riggle, 1997).

Another part of the operation is called the “nursery,” where earthworms (Eisenia fetida) are grown prior to their introduction into the vermicomposting systems. Earthworm castings have been sold in 2 lb. (.9kg), 10 lb. (4.5kg), and 25 lb. (11.3kg) bags since 1995 under the name Vermicycle™. Local markets such as garden centers, supermarkets, and organic farmers have been very receptive to the product that costs twice the price of compost. Vermicycle Organics is also looking to export its vermicompost to foreign countries such as Japan, and is considering vermicomposting feedstocks other than swine manure in order to market earthworm castings to certain Muslim countries.

Figure Vermicycle's Colorful bag touts Nature's Ultimate Plant Food

The principal focus of the company is to convert pig manure into earthworm castings to be sold under the trademarked name Vermicycle™ (Nature’s Ultimate Plant Food). In the eastern portion of North Carolina, it’s not unusual for hog farms to have 5,000 to 10,000 animals per acre, in a state that is home to over nine million hogs. For the most part, manure from the swine houses is sent to lagoons, a practice that results in odor complaints, groundwater contamination and other environmental concerns. Hog farms usually flush droppings directly into lagoons where bacteria consume many of the nutrients over time. The remaining liquid is then sprayed on fields, usually of Bermuda grass, which is later harvested as cow feed. Vermicycle Organics’ program, while not solving all the farmers’ problems, reduces nutrients in the liquid waste by as much as 50 percent. And it may reduce the number of acres farmers need for spraying the treated liquid. “There’s no doubt that any type of technology that removes nutrients from the liquid manure prior to the lagoon is going to have a positive impact on water quality…as well as odor,” said Mike Williams, director of the Animal and Poultry Waste Management Center at N.C. State University who also served on the Governor’s Blue Ribbon Study Commission of Animal Waste in 1994-95. In an August 1996 article on Vermicycle Organics, published in The Charlotte Observer, Williams called Vermicycle’s process one of the more promising among 500 or so commercial hog-waste management proposals he has received.

Vermicycle Organics’ three partners obtained an $80,000 Small Business Administration loan in 1995, purchasing 8,000 pounds of earthworms and building test beds at Clover M Farm in Wilson, North Carolina. There they refined their process for producing castings from hog waste. As it exits the hog house, the waste is diverted to a machine called a separator that squeezes liquids from the solids. The liquids flow into a lagoon and the solids are temporarily placed on a concrete pad where the remaining effluent also runs off into the lagoon. Then the solids are transferred to worm beds, measuring from 2-4 feet wide and 200 feet long. After several months within the beds, the material is sifted, separating earthworms from their castings. The end product is then packaged in 2-pound, 10-pound and 30-pound plastic bags imprinted with the yellow-blue-and-green Vermicycle logo. Trucks then deliver the product to 30 garden centers, grocery stores, farms and nurseries in the Carolinas. Stores sell a 2-pound bag for between $3 and $4, and the 10-pound bag for $15 or $16. The 30-lb. sack retails for $24.99.

Figure Earthworm Castings from hog manure

The partners rejected using an open field method of vermicomposting as unsuitable due to difficulties with weather and poor end product. So they tried enclosing the worm beds in 30-foot by 200-foot greenhouses, each containing about six worm beds with wooden sides. A spreader delivers manure to the beds while moisture and temperature are managed using shade cloth, an automatic mister, fans and greenhouse curtains. Besides the beds at Clover M Farm, Vermicycle Organics built 12 greenhouses and several dozen worm beds at another farm in Wilson. That operation was scaled to produce 80,000 to 100,000 pounds of castings per year. At full capacity, a centralized processing facility was planned to include 16 greenhouses that would handle around 7,500 tons of manure per year.

After experiencing problems due to severe weather and eventual changes within the partnership, Tom re-located his operation to yet another farm in eastern North Carolina. Greenhouses were again constructed, designed to follow the patterns established earlier. Here, as Rhonda Sherman-Huntoon, an Extension Solid Waste Specialist of North Carolina State University in Raleigh reported in the November 2000 issue of BioCycle, “the beds that run the length of the greenhouse extend nine-inches into the ground and eight inches above ground. The sides of each bed are lined with high-density polyethylene reinforced with boards and steel pipes. A rubber hose that runs along one side of each bed has nozzles that spray automatically for 15 minutes daily. There is enough space between each bed to accommodate the wheels of a tractor with a manure spreader driven over each bed to distribute the hog manure solids. Worms are fed daily, averaging 1,000 pounds of manure per bed each week.”

At one time Christenberry experimented with the design of the Continuous Flow Reactor developed by Dr. Clive Edwards and his colleagues at Rothamsted in the United Kingdom during the 1980s. But Christenberry did not find the elevated-bed system compatible with his own ideas of vermicomposting hog manure, preferring to accept the advantages and disadvantages of setting up worm rows upon soil. Sherman-Huntoon writes, “One advantage of this system is that if the worm beds get too hot, worms can burrow deeper into the bed where the temperature remains below 75° Fahrenheit. Another advantage is the system can be left alone for up to three days, as compared to automated reactors that need to be checked daily for moisture and temperature levels. A disadvantage is that the worms and castings must be separated manually. Migrant workers use pitchforks to remove the top 4 inches of the beds for use in starting new beds. Pitchforks and shovels are used to harvest the finished castings, which are then run through a trommel screen to separate the worms.”

The company engaged in market research that revealed that the public’s awareness of earthworm castings and their benefits was low, but that interest in good quality organic fertilizers is growing. From a market trial, Vermicycle Organics found that 70 percent of the targeted retailers accepted an initial stocking of their product, despite a retail price that was more than twice that of compost. The company also found that the largest potential markets were in foreign countries, such as Japan.

How have customers responded to Vermicycle? “I was skeptical,” said Jerry Howard, a wholesale plant producer. “Vermicycle overwhelmed me with its results. My plants had double the foliage and buds over my control plots.”

Edwin Jordan, a greenhouse propagator said, “Propagation is a delicate procedure that fertilizers can jeopardize. Vermicycle doubled my root growth without harming my plants.”

“We sold quite a bit of it this spring,” said Jesse Campbell, owner of Campbell’s Greenhouses, in Charlotte, NC. Campbell said he tested the product before agreeing to carry it. “We used it on bedding plants and we got remarkable growth on them.”

Consumers spent an estimated $22.2 billion on lawn and garden supplies in 1995 and that figure is growing several percentage points a year, according to the Burlington, Vermont-based National Gardening Association. Bruce Butterfield, the association’s research director confirmed, “the interest in environmentally friendly products certainly is something that’s particularly hot.”

Research performed at The Ohio State University with pig manure castings produced by Vermicycle Organics showed that this earthworm feedstock usually outperformed castings from cow manure, paper waste and food waste. In July 1998, Dr. Scott Subler, Dr. Clive Edwards, and Dr. James Metzger published “Comparing Vermicomposts and Composts,” in BioCycle: The Journal of Composting and Recycling. At the conclusion of their study, after testing 13 different treatments of various composts and vermicomposts, the authors stated: “We have found that, just like composts, vermicomposts have the potential for improving plant growth when added to soil or container media. Furthermore, it appears that there may be important differences between specific vermicomposts and composts: both in the nature of their microbial communities, and in their effects on plant growth. From the studies that we have described here, and from others that we have conducted, it is apparent that the pig solids vermicompost we tested consistently outperformed the other vermicomposts and composts. (emphasis added) We are still attempting to identify the biological mechanisms responsible for the consistent performance of this material, as well as for the unique and remarkable plant growth responses that continue to be widely observed and reported for other vermicomposts and earthworm castings.”