The microbial food safety risks from using raw animal manure and other untreated biological soil amendments of animal origin (BSAAOs) are well documented. Nevertheless, some growers still rely on untreated BSAAOs for economic and practical reasons, and recent research has shown that their use varies widely by geographic region, farm size, and type of crop/manure. The Produce Safety Rule specifies that BSAAOs must be applied in a manner that does not contact covered produce during application, but has reserved the specific harvest interval(s) after application until further research and a risk assessment are conducted. In contrast, application of FSMA-compliant composted or treated BSAAOs to soils for production of fresh produce is expected to result in reduced risk of pathogen contamination with minimal public health risk. But, unexpected risk may occur from cross-contamination or regrowth of pathogens.

• Evaluation of application intervals for the use of untreated animal manure as a soil amendment in conventional and organic fresh vegetable production (also funded through USDA Specialty Crop Research Initiative and USDA Organic Research and Extension Initiative)
• Prevalence and levels of Salmonella and STEC in raw manure in different geographic locations of the western and eastern U.S.
• Persistence and transfer of generic coli and STEC on organic farms that integrate rotational sheep grazing and fresh produce production (also funded through Center for Food Animal Health)
• Understanding and enhancing the safe use of biological soil amendments: Evaluating potential microbial risks from commercial heat treated poultry pellets