P1-180 Validation of Waiting Intervals for the Incorporation of Untreated Biological Soil Amendments of Animal Origin into Soil Where Specialty Crops are Grown in Ohio

Sunday, July 26, 2015
Exhibit Hall (Oregon Convention Center)
Michael Kauffman, The Ohio State University, Wooster, OH
Anil Persad, The Ohio State University, Wooster, OH
Jeffrey LeJeune, The Ohio State University, Wooster, OH
Introduction:  Biological soil amendments of animal origin provide a valuable source of fertilizer for growing fruits and vegetables.  At the same time, animal manures may contain foodborne pathogens that can result in contamination of produce. The survival of pathogens in soil-applied manure is dependent upon a number of factors including the composition and characteristics of the manure and the soil and environmental conditions.

Purpose: The purpose of this study was to model the survival, under environmental and management conditions in Ohio, of microbial indicators of fecal contamination (Escherichia coli) and pathogens (Escherichia coli O157, Listeria monocytogenes, Campylobacter jejuni, Salmonella spp.) in soils amended with bovine manure.

Methods: Untreated bovine manure (mixture of feces, urine and used bedding materials) was applied at a rate of approximately 2 ton/acre on fields (n = 3) intended for growing produce with predicted harvest dates to coincide with 270 days, 180 days, 120 days and 90 days prior to harvest.  Prior to planting, the soil was turned following traditional Amish cultivation practices.  E. coli counts and pathogen prevalence was monitored monthly following application of manure. 

Results: Results from the first season demonstrated decline generic E. coli counts in soils following application and tillage.  Counts did however increase after tillage without that application of additional soil amendments.  Total E coli counts in soils at the time of harvest did not vary with the time since prior manure application.  Pathogens were infrequently recovered from both amended and non-amended soils.

Significance: The survival rate of E. coli and pathogens calculated from this study provide valuable data to populate risk models critically needed to predict food safety risks associated with the application of untreated biological soil amendments of animal origin, especially under the conditions typical of specialty crop production in Ohio.