Final Report for FW06-032
Worms can be excellent “workers” on a small farm, and at something like $18 per pound in market value, they are a high-value commodity. However, working with red worms did not increase our poultry productivity. It took time and space away from our main enterprise, and mostly we felt like we were bringing in an expensive input rather than harvesting anything of additional value.
We were unable to invent a method for more efficient loading of chickens per acre on pasture or faster rotation of chickens. The worms had no impact on hygiene or odor when added to the chickens’ living space. The chickens ate the worms, the worms couldn’t keep up with the volume of fresh manure, and as fresh manure began to compost, the high temperature killed the worms.
Addition of red worms had no effect on parasite or coccidiosis control. On the suggestion of our technical advisor, we did additional experiments to determine whether we could develop a viable living co-product such as living vermicompost. However, our most space-, labor- and cost-efficient method of disposing of chicken manure and chicken bedding turned out to be simply a traditional outdoor compost pile.
On our very small acreage we do not have sufficient space or equipment to take on another major enterprise of vermiculture at this time. For farms that have an unused barn, a dump truck for collecting and hauling manure, and a large tractor, vermiculture may be an ideal additional enterprise for getting more value out of these unused resources.
The objectives of this research were to characterize an efficient vermiculture method to more quickly dispose of chicken manure. Our primary motivation is improved economics of loading chickens-per-acre and faster rotation of chickens on pasture. The secondary motivation was hygiene and cleanliness of the chickens’ living quarters and reduction of odor. The third motivation was to increase the population of worms for the possible dual purposes of feeding the chickens and of having surplus worms and worm castings as an additional saleable agricultural product. The fourth motivation was to look at the effect of the worms on parasite control.
We were unable to invent a method for more efficient loading of chickens-per-acre on pasture or faster rotation of chickens. Red worms are compost worms and prefer to live just below the surface of compost, feeding mostly on decomposing inputs such as kitchen scraps, windfall fruits and vegetables, and small amounts of fresh manure. They did not thrive in the full sun conditions of a grass pasture, the environment of heavy soils and living grass rather than compost, or an exclusive diet of fresh chicken manure and dropped chicken feed.
The highly acidic environment of the manure did not support the worms. Additionally, our 500 free-range laying hens ate nearly all of the worms immediately.
We also tried earthworms. Although they did thrive deeper in the soil, their presence had no measureable impact on the recovery time of the grazed pasture following the presence of chickens on the pasture because they did not come up to the surface to process the manure crust.
The worms had no impact on hygiene or odor when combined with the chickens. The worms could not keep up with the volume of fresh manure and as fresh manure composted, the worms died of the heat.
We got the same result whether the chickens were raised outdoors on grass, indoors on straw, or indoors on wood shavings. However, when either the straw or wood shaving beddings were composted in traditional compost piles with the chicken manure, we had good breakdown of the components, complete odor elimination, and healthy living compost. This result, however, was independent of whether red worms had been introduced to the compost pile.
A further difficulty was moisture and temperature. In the Willamette Valley of Oregon, it is usual for us to have 40 consecutive days of no rain during the summer. These hot dry days of summer dried out our compost, which thus required daily watering to keep the worms alive. In the winter, we typically have 40 days or more of rain and cold temperatures, which forced the worms into dormancy whether they were in the outdoor compost pile or in the heated barn.
Based on the suggestion of our technical advisor, we did additional experiments to determine whether we could develop a viable living co-product such as living vermicompost. In these experiments we actually combined chicken manure from our broiler operation along with cow manure from our raw dairy. However, the straw bedding for the cows, combined with their manure, was already composting nicely in a traditional compost pile and this experiment only added work without really creating a new product.
BENEFITS OR IMPACTS ON AGRICULTURE
For our farm, which is run only by husband, wife, and one worker, the additional work required for the additional enterprise of vermiculture was not practical. Traditional composting proved to be far less labor intensive and provided the expected result of composted chicken manure and elimination of odor and disease.
We believe that our experiments will prevent other farmers from repeating our mistakes. We believe vermiculture is a viable business, but that worm farming should be viewed realistically as a full-time enterprise requiring the care and feeding of an additional species of livestock, and not as an easy adjunct to existing farm enterprises.
It’s likely that for an operation raising poultry in confinement, combining vermiculture with poultry could take what is currently a waste product and perhaps a source of odor and disease and convert it into an additional revenue source.
Further, we think it’s likely that other species of worms such as native earthworms, which live in the pasture soil, can be encouraged through organic and biodynamic farming methods to increase their population and vigor, and that tilling top-crust manures into the soil would make that manure available to the worms. It may rather be possible that “cow pies,” which tend to attract fly eggs, might be tilled under at just the right moment in the flies’ life cycles to disrupt fly populations.
We have a further hypothesis that organic and biodynamic methods for increasing the earthworm populations more generally in a large area such as a pasture would probably contribute to healthier pastures, more biological diversity in the pasture, and more rapid recovery from grazing by chickens.
Another possible future experiment would be to first work on increasing the population of the worms, and then till the manure crust into the topsoil to break up the crust and to mix the manure and dropped grains with the soil, presumably making these nutrients more accessible to the worms. This would also likely require re-seeding the pasture, which may or may not contribute to the goal of shorter rotation times before returning the next batch of chickens to that area of the pasture.
Our public website, www.kookoolanfarms.com, has a page on worms and vermiculture, including our grant proposal and final report.