Location: Environmental Microbial & Food Safety Laboratory
Project Number: 8042-32420-009-014-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2020
End Date: Aug 31, 2025
Objective:
1. Advance scientific basis for the wait time between application of raw (untreated) manure and crop harvest for three fresh produce types (tomato, spinach, radish) on USDA-National Organic Program certified farms using field and laboratory experimental approaches in microbiology.
2. With organic growers, conduct on-farm assessments for soil health and analyze response relative to the presence of fecal bacterial pathogens in raw manure, manure-amended soils, and crops grown on several and soil in the mid- produce-growing regions.
Approach:
An integrated, three-prong approach will be employed to address the major objectives defined. I) ARS will develop experimental field plot designs, inoculation and manure amendment protocols, bacterial detection, identification, microbial community analytic procedures, and data management/backup and transmittal criteria and procedures during the study periods for the plot and farm soils, manure, water, and fresh produce commodities, at UMES and several Mid-Atlantic grower farms. II) The Cooperator will conduct sampling, plot management and microbial analyses consistent with the detailed ARS procedures. III), Raw and processed data from all analyses will be reviewed by UMES and ARS, and statistical analyses conducted with consultation from ARS biostatistician. The microbiological technical personnel of Cooperator will maintain close contact with the ARS investigator. Specifically, the Cooperator will calculate soil nutrients, soil microbial population responses over time, transfer of inoculated microbes from soil to produce, soil health assessment indices, and competitive inhibition of inoculated microbes in soil extracts, with a focus on establishing the relationship between E. coli populations survival in soil from the time of manure application to detection on harvested fruits at 90 and 120 days post-manure application. The intent will be to identify factors in organic soils that strongly influence rapid decline and reduced transfer of E. coli from manured soil to harvested produce. Computations will address microbial inactivation rates, overall soil health, and soil microbial inhibition of E. coli, Salmonella, and Listeria monocytogenes in organic field production of three model fresh produce commodities (tomatoes, spinach, and radishes). UMES and ARS will work jointly to prepare manuscripts for peer-review journals and materials for outreach activities with organic growers/farmers.
