By Joe Roberts
As avian influenza continues to ravage U.S. flocks, the grim reality is that safe, fast disposal of deceased infected birds is necessary.
Rachel Wieme, an Extension specialist with Washington State University, was tapped by the USDA in early February to provide guidance to Missourian poultry farmers as a certified subject matter expert on animal mortality composting.
“Despite these unfortunate circumstances, we can generate a valuable soil amendment that benefits farms and the environment,” said Wieme, a WSU Extension regional agronomist in Walla Walla County. “The main goals are biosecurity and virus containment, and on-site composting is efficient at both.”
In early 2022, the highly pathogenic avian influenza virus was detected in the U.S. Though the U.S. Centers for Disease Control and Prevention considers avian flu a low risk to human health, it is often fatal for birds.
The recent deaths of more than 4 million birds across 20 Missourian farms are a testament to the virus’s brutal nature.
To avoid wasteful disposal of the high number of mortalities through burning, burying, or hauling to a landfill, many farmers in the state turned to the USDA’s compost protocols and support for help. Keeping the carcasses out of the landfill means less methane generation — a potent greenhouse gas — and nutrients can be recycled for on-farm use. Burning generates carbon dioxide and an unpleasant smell, while burying carries the risk of contaminants leaching into the environment.
Though composting does release some carbon dioxide, overall, the amounts are much lower in comparison with other means of disposal. Composting has the potential to be an environmental and economic win-win for some operations.
“Composting allows us to not only contain and deactivate the virus, it also allows the materials to be repurposed rather than contributing to landfill waste,” said Wieme. “We started by building lines of piled organic matter, called windrows. Each windrow goes through two two-week phases and are turned after each phase.”
The windrows’ mixture of woodchips, poultry litter, manure, and mortalities are continuously monitored for temperature and visually evaluated for decomposition. The piles generate enough heat from the frenzy of microbial feasting to disable the virus and break down the organic materials.
The result is a crumbly, dark, earthy-smelling soil amendment that provides crops or fields with a rich source of nutrients.
Back home, Wieme provides similar education and advice to Washington state farmers and ranchers in her WSU Extension role.
“While animal mortality is a part of our food system that people don’t often want to think about, these types of catastrophic events force us to consider it,” said Wieme. “There is a level of routine mortality in raising animals that occurs. It’s an opportunity for people to learn more about our agricultural and food systems.”
Wieme credits mentor and fellow soil scientist Lynne Carpenter-Boggs, chair of WSU’s Department of Crop and Soil Sciences, for leading the projects that allowed Wieme to gain the composting certification. She said she also learned a lot from the experience in Missouri.
“I’m grateful I had the opportunity to apply my training during this outbreak,” said Wieme. “I relied on my Extension outreach skills while working with the growers and operators on the farms in Missouri, and I’m bringing back knowledge and experience that will contribute to my work to build more resilient food systems in Washington state.”
Source : wsu.edu