Organic farmers seek to provide healthy, nutritious food to environmentally-conscious consumers. Thus, it is obviously critical that the produce they sell is safe to eat. In recent years, food safety has been endangered by produce contaminated by harmful E. coli strains or other human pathogens. Wildlife are believed to be one source of this contamination, because deer, songbirds, rodents, or other animals that defecate in a field can unwittingly introduce pathogenic E. coli. To reduce this risk, farmers feel increasingly pressured to remove all natural vegetation from their farms, erect large deer fences, and even drain ponds – all to chase off wildlife. Of course, this goes against farmers’ knowledge that increasing biodiversity is the best way to conserve natural enemies and improve natural pest control.
Snyder-lab PhD student Matt Jones is leading an effort to learn more about the sources and fates of human pathogens on mixed-vegetable farms from British Columbia to southern California. Half of the study farms are traditional vegetable-only operations, while the other half mix vegetable and lifestock production (livestock provide free fertilizer and valuable meat products for CSA and other customers). We are examining whether biodiversity is the solution to, rather than the cause of, human-pathogen outbreaks on these farms. Our hypothesis is that species-rich communities of feces-consuming dung beetles and other insects, and soil microbes, can rapidly devour feces and indirectly kill harmful E. coli. Matt, his collaborators, and a large group of cooperating farmers, have just been awarded a half-million-dollar grant from USDA’s “Organic Transitions” program in support of this work.
Key collaborators include Snyder-lab postdoc Daisy Fu, Tom Besser in WSU’s College of Veterinary Medicine, John Reganold in WSU’s Crop and Soil Sciences Department, David Headrick in the Horticulture
Department at Cal Poly U, and Alex Stone and her eOrganic team
at Oregon State University.