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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Environmental Microbial & Food Safety Laboratory » Research » Research Project #427485

Research Project: Persistence of Enteric Pathogens in Manure-amended Soils in Northeast U.S. Produce-Growing Environments

Location: Environmental Microbial & Food Safety Laboratory

Project Number: 8042-32420-006-15-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Sep 29, 2014
End Date: Aug 30, 2018

Objective:
Determine the persistence of enteric pathogens (Escherichia coli) in soils in the Northeast U.S. (Vermont) and their potential transfer to produce commodities; if manure application techniques affect enteric pathogen survival in amended soils; and determine if enteric pathogens present in manure-amended soil can be transferred to leafy green vegetables and their persistence on these vegetables.

Approach:
Experimental field plots in Vermont will be identified with common soil types specific to Vermont. Field studies will be conducted by Cooperator (University of Vermont) personnel. Regional untreated soil amendment (UTSA) (manure) application schedules will be selected such that the study duration will coincide with the initial application of manure to agricultural fields. UTSA from regional livestock herds will be used and incorporated or applied to soils to provide appropriate levels of nitrogen (N) in accordance with specified regional fertilization and cropping practices. Application rates of UTSA will be bracketed around the UTSA and soil N content and the crop recommendations for the area. Low and high levels of UTSA N (i.e., less and more UTSA applied, respectively, than required to support crop N needs) may lead to lower or greater native populations of fecal indicator bacteria (E. coli) and potential pathogens, thereby providing two levels of inocula corresponding to the two levels of UTSA application rates. As in the current Mid-Atlantic Manure Pathogen Survival Study (MPSS), experimental plots will be designed and devised in a manner that is not disruptive to commercial or university operations and that provide for repeated measurements and consistent microbial and nutrient analyses. Natural populations of commonly used indicators (like E. coli) and other pathogens (like non-O157 enterohemorrhagic E. coli (EHEC), Salmonella spp., and Listeria monocytogenes) present in UTSA will be identified and tracked over the course of 270 days in specific plots using environmental microbiology recovery techniques. Experimental schedules previously employed during the MPSS will be employed (6 days of microbial analysis in the first 30 days of the study, and then once every 30 days thereafter). Microbial analysis techniques adapted from current MPSS studies and other studies involving biosolids, manure, and compost at EMFSL will be employed to recover microorganisms. If available at the same or nearby locations for the field study, UTSA application to high tunnels used for fruit and vegetable production in Vermont will also be tested for populations of a naturally present indicator bacteria (E. coli) and other pathogenic microorganisms. Nutrient and moisture data of soil and UTSA, along with climate data will also be collected throughout the study and included as correlation factors in the final data analysis.