Farmers need more research on biological soil amendments wait times

Photo Credit: Gabriel Jimenez

An article published in the most recent issue of the Organic Farmer magazine highlights a partnership between The Organic Center and UC Davis School of Veterinary Medicine, and makes a call for more research on food safety risks of using raw manure on organic farms. The National Organic Program prohibits organic farmers from using synthetic fertilizers for nutrient management, which means organic farmers often rely on animal-derived, organic soil amendments. These biological amendments do more good than just adding nutrients to the soil, such as enhancing water-holding capacity, reducing erosion and improving structure to defend against drought and flooding. However, it is important to make sure they are used in a way that eliminates food safety risks. To reduce the risk of foodborne pathogen outbreaks to fresh produce, there are rules set by the Produce Safety Rule within the Food Safety Modernization Act that require raw manure to be handled and applied in a way that does not contact the target crop. The National Organic Program standards go further to require wait times up to 120 days before application of raw manure to reduce risk of contamination. Because there are many factors that affect the risk of contamination, including the type of animal manure, the way the animals were raised, soil properties of the ground on which the manure is applied, and other physical conditions such as temperature and rainfall, this article makes a call for more research to examine how organic farm management may mitigate risks of foodborne pathogens. More research is needed to support the rules for the use of biological soil amendments that protect consumers and allow organic farming to be feasible.