BLUFFTON, Georgia – A multigenerational family-owned farm striving to be a no-waste operation is one step closer with the help of an indigenous insect.
White Oak Pastures, which raises, processes and packages livestock and poultry on-site, received a Southern Sustainable Agriculture Research & Education (SARE) Producer Grant to turn the black soldier fly into a value-added tool of making compost, while also serving as a protein source for chickens.
"We are taking an unwanted by-product of livestock processing that has a negative value and creating a higher and better use for it through black soldier flies by creating two value-added products: compost and supplemental feed," said farm owner Will Harris. "And we are creating these products using a resource that is already available to us and without using any energy."
The black soldier fly, native to North America, exhibits characteristics that would be considered beneficial in agriculture. The adult fly does not bite, nor is it known to carry any diseases. In addition, the larvae (also known as mealworms) are scavengers, thriving on several kinds of decaying matter such as carrion, manure, plant refuse and waste products. With a dry weight protein content of roughly 42 percent and a fat content of about 34 percent, the larvae also make ideal inexpensive feed for chickens.
For project investigators Hilary Halford and Tripp Eldridge, the black soldier fly perfectly aligns with the 1,000-acre farm’s sustainable agriculture practices of organic production, multi-animal rotational grazing, environmental stewardship, and animal welfare.
"The SARE grant is giving us an opportunity to explore the opportunities that this native species affords us and potentially create a system that can produce an inexpensive feed for our poultry while helping us meet our zero waste goals through compost development," said Halford, the farm’s office manager.
The project calls for "farming" the black soldier fly larvae, either through on-farm collection or encouraging the females to lay eggs in corrugated cardboard incubators, and caring for the larvae until they are large enough to be transferred to suitable decaying matter. Eldridge, the organic farm manager, is using ProtaPods as composting containers.
"Once we get the larvae in the ProtaPod, they are easy to collect. They self-harvest, meaning that when they are ready to pupate, they will crawl out of the compost up a ridge around the container and then drop into a bucket that we’ve got set up," said Eldridge. "We then either allow the mature grubs to re-populate the area or feed them to the chickens."
The challenge, so far, said Eldridge, is maintaining a sustainable population of larvae at a volume suitable for waste processing and a volume high enough to be harvested for chicken feed. Moisture content appears to be big factor in the survivability of the larvae.
"Once we get our population secured and maintained, then we’ll be exploring a number of objectives, such as the ratio of larvae to compost production, how much larvae it takes to make a difference in the growth rate of the birds, what is the best processing system, and cost comparison of larvae as feed compared to other supplements," said Eldridge.
Whether or not the current system works, Harris has big plans for the black soldier fly in his farming operation.
"They are here for a reason," he said. "It’s all about taking responsibility for your waste."
White Oak Pastures re-purposes what it produces on the farm by creating manure compost, recycling all the wastewater, and using an anaerobic digester, which generates 1,000 gallons of liquid fertilizer a day. In addition, the farm houses passive solar water-heaters on roof buildings to heat the water used in livestock processing, and a 50,000-watt solar voltaic array to power the processing plant.
In addition to livestock, the farm produces organically certified vegetables for a 50-family CSA.
For more information on White Oak Pastures, visit www.whiteoakpastures.com.
The black soldier fly, native to North America, exhibits characteristics that would be considered beneficial in agriculture.