Source: UNIV OF CALIFORNIA (VET-MED) submitted to
MULTI-REGIONAL RISK ANALYSIS OF FARM MANURE USE: BALANCING SOIL HEALTH AND FOOD SAFETY FOR ORGANIC FRESH PRODUCE PRODUCTION
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
EXTENDED
Funding Source
Reporting Frequency
Annual
Accession No.
1010610
Grant No.
2016-51300-25724
Project No.
CALV-12117374
Proposal No.
2016-04422
Multistate No.
(N/A)
Program Code
113.A
Project Start Date
Sep 1, 2016
Project End Date
Aug 31, 2021
Grant Year
2016
Project Director
de Andrade e Pires, A. F.
Recipient Organization
UNIV OF CALIFORNIA (VET-MED)
(N/A)
DAVIS,CA 95616
Performing Department
Pop. Health & Reproduction
Non Technical Summary
Certified organic producers rely on manure-based soil amendments for crop nutrients and to maintain soil health. However, use of untreated animal manure in fresh produce cropping systems may introduce foodborne pathogens and increase the risk of foodborne illness for consumers. Few scientific studies documenting pathogen die-off in organic systems are available to support specific wait periods between manure application and crop harvest. The proposed project uses an integrated research-extension risk-based approach to address an urgent and critical need to assess current manure use by organic growers and evaluate pathogen survival time relative to soil health status. Specific aims include: 1) Risk analysis of on-farm practices associated with persistence of pathogens on organic farms using manure-based soil amendments in diverse cropping systems; 2) Determine the relationship between soil health and pathogen survival in organically managed produce fields amended with raw animal manure; 3) Develop a comprehensive on-line and in-person (mixed model) outreach program to provide technical and systems-based produce food safety training for the organic farming community. The long-term goal is to improve the microbial food safety of fresh organic produce (e.g., leafy greens, tomatoes, root vegetables) grown in soils amended with raw manure. The overall objective is to develop a customized risk-assessment based on good agriculture practices, rigorous microbial testing, self-assessment of soil health, and environmental factors. The outcomes of this project will benefit organic farmers and consumers by providing science-based strategies to maintain the value of raw manure soil amendments while limiting food safety risks.
Animal Health Component
50%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
71201101060100%
Goals / Objectives
The long long-term goal of this project is to improve the microbial food safety of fresh organic produce grown in soils amended with raw manure and typically eaten raw (e.g., leafy greens, tomatoes, root vegetables). The overall objective is to develop a customized risk-assessment based on good agricultural practices, rigorous microbial testing, self-assessment of soil health, economic impacts (cost/benefit) and environmental factors to maintain the value of raw manure soil amendments while limiting food safety risks. The specific objectives are: 1) Assessment of on-farm practices, environmental factors and soil health associated with the persistence of pathogens among organic farms using raw manure as a soil amendment, in the diverse conditions of organic farming in three organic regions of the U.S.; 2) Determine the relationship between soil health and pathogen survival in organically grown fresh produce fields amended with raw animal manure in multiple U.S. regions; 3) Develop an outreach program targeting organic producers using biological soil amendments of animal origin. We will accomplish these goals and objectives by increasing the understanding of persistence and survival of foodborne pathogens, their ecology, and relationship to soil health, which will be used to develop targeted mitigation strategies for risk management in organic produce environments (e.g., customized on-farm food safety approaches). This project will also develop a nationwide and regional outreach program available to organic growers to reduce the risk of introduction/persistence of pathogens in fresh produce production and preserve the benefit of raw manure use in organic and sustainable agriculture.
Project Methods
The overall goal of the Activity 1 is to develop a customized food safety risk-analysis for contamination of produce in organic agriculture. A longitudinal study design will be conducted over two-years to capture two crop cycles and time-variable factors in three regions: West, Midwest and East. A total of 27 certified organic farms [NOP certified organic; produce at least one of the following fresh crops: leafy greens (e.g., lettuce, spinach), root vegetables (e.g., carrots, radish) and fruits (e.g., tomatoes, cantaloupe or melons); use raw or untreated manure of dairy cattle, horse or poultry sources in produce fields] will be included in the study. Repeated sampling of composite manure, composite soil, water and produce will be conducted in order to assess the prevalence and survival of foodborne pathogens (Salmonella, STEC, non-STEC, and L. monocytogenes) and indicators of contamination (E. coli die-off). Soil health will be evaluated (microbiome analysis, general soil chemistry and soil health self- assessment and scoring). Management and farm practices (e.g., demographics, size, irrigation, crops, soil amendments, soil health, etc.) and environmental factors (meteorological and landscape data) will be recorded during the study period. Multilevel logistic regression and zero-inflated multilevel effect negative binomial models conducted to determine the association between on-farm management factors, manure factors, soil factors (health and level of contamination), environmental factors and landscape on fresh produce in each of the following outcomes of interest: 1) the prevalence of pathogens (Salmonella, STEC and L. monocytogenes) and 2) levels of microbial contamination indicators (i.e., generic Escherichia coli survival or die-off rate) in fresh produce.A customized self-risk assessment will be displayed and mapped graphically and in tables within the "MU-safe" dedicated site (within the web-based platform referred to as Disease BioPortal ® and a user-friendly mobile application or "App"). The self-risk assessment will account for multiple factors (e.g., on-farm management factors, soil health, survival of pathogens environmental and landscape factors) that are significantly associated with the persistence and prevalence of pathogens in fresh produce crops. Finally a cost effectiveness and economic analysis will be conducted to evaluate different strategies employed based on soil type, proximity to livestock production facilities, climate, specific crop, availability of alternatives, and costs.The Activity 2 will take place in 3 certified organic centers (West, Midwest and East). The overall goal of this activity is to determine adequate wait times between manure application and crop harvest on organic farms. Experimental field trials (randomized complete block) will be conducted to determine appropriate application intervals for biological soil amendments of animal origin on organic farms. The field trials will include rpeated testing of soil plots and manure (dairy manure, poultry litter and horse manure) as well as at plant harvest (spinach, radish and tomatoes) to assess initial presence and die-off of pathogens and contamination indicators (E. coli (gEC). Soil microbial community profiling and competitive inhibition assay will be assessed under different manure treatments. Analysis of variance, multivariate analysis will be used to evaluate the treatment effects on pathogen survival and die-offs.The overall goal of the Activity 3 is to develop a nationwide and regional outreach program available to organic growers to reduce the risk of introduction/persistence of pathogens in fresh produce production and preserve the benefit of raw manure use in organic and sustainable agriculture. Relevant farmer-focused outreach and extension efforts aimed directly at organic farmers through the development and presentation of a webinar, continuing education modules and fact sheets for organic growers. The outreach plan is multi-tiered to ensure constant stakeholder engagement (project advisory committee and stakeholder groups) and effective results dissemination. It will incorporate input from the during the entire course of the outreach process. The outreach will be evaluated using both quantitative and qualitative metrics.

Progress 09/01/19 to 08/31/20

Outputs
Target Audience:The target audiences reached include various stakeholders in organic agriculture and produce food safety, including organic farmers, researchers, extension specialists, extension agents, policy makers, experts and industry working in organic agriculture. They were reached as part of the conferences, workshops and informal education activities (field days, one -to-one meetings with farmers) delivered through presentations at national and international meetings and conferences. To reach our target audience the Organic Center disseminated a press release to publicize the planned research. The Organic Center also developed a web portal where a description of the project, updates, and information has been posted. We also launched and maintain a social media campaign surrounding the research via The Organic Center and Organic Trade Association Facebook and Twitter accounts, A unique Twitter account was developed specifically for this project as well. The combined reach of our organizations' social media pages is followed by over 149,412 individuals onFacebook, and over 70,200 followers onTwitter. The Produce Safety Alliance also maintains several social media platforms, which have been used to highlight updates on this project, including stakeholder presentations and resource updates. The Produce Safety Alliance's Facebook, Instagram, Twitter, and YouTube accounts reach 2,091 (Facebook) 277, 506 (Twitter), and 286 (YouTube) followers, respectively. Changes/Problems:The research team is working to identify a new economist to collaborate in this project. Due to the Covid19, the microbial population analysis was delayed, but is expected to be completed during this year, depending on restrictions of lab working in each institution. What opportunities for training and professional development has the project provided?The project provided support for graduate/post-doctoral and undergraduate research, thus helping to build capacity for future professionals in microbiology, epidemiology and food safety. Dr. Pires mentored one PhD student, 1 junior specialist and 3 undergraduate students at UC Davis. A master student (co-mentored by Drs. Hashem, Millner, and Pires) graduated from UMES. How have the results been disseminated to communities of interest?Additionally, we are communicating with the public through a website, which was redesigned in 2020 to include a short summary of the project, a detailed description of the project, information about the research team, and a list of presentations and publications that have come out of the project. The website also includes a News & Updates page, which includes updates with pictures from the field, announcements about upcoming events, and extension material. We have also leveraged the project outreach with the Organic Center's Google Ad Words Grant, which provides up to $40,000 of funding per month for Google Ad Words. This campaign has generated a total of 275,027 clicks and 2,674,981 ad views over the last year. We are using social media to ensure that we reach a wide variety of stakeholders via the Organic Center and Organic Trade Association social media pages. The combined Twitter following for these organizations is 70,200 and the Facebook following is 149,412. The project has also been communicated through in-person meetings with industry and farmer partners. For example, it was featured at the Organic Confluences Conference, which focuses on collaborative solutions to organic sector challenges. Finally, the project has been publicized in several Newsletters, including the Organic Center Scoop, which goes out to 23,689 individuals, and the Organic Trade Association Newsflash, which goes out to 3,500 subscribers. The project was also publicized in the Organic Report, a magazine with a readership of over 21,000. The Organic Center has also been ensuring the project outcomes reach industry members, including the Organic Trade Association's Produce Safety Council. Finally, two educational outreach modules are in development to help reach a broad array of stakeholders: "Science-based composting practices" and "Guidelines for manure use in produce production to enhance soil health". Parts of the science-based composting practices module, which addresses manure treatment strategies and commonly-used non manure-based soil amendments, have been presented in draft form and are undergoing internal review for finalization. Guidelines for manure use in produce production to enhance soil health is being drafted for initial review. The Produce Safety Alliance has been in frequent communication with the researchers to ensure data from this project is being incorporated where appropriate into both modules. This includes the manure and soil health research from Activities 1 and 2 of this project. What do you plan to do during the next reporting period to accomplish the goals?Activity 1 (farm survey): We plan to finalize the statistical analysis to assess the risk factors with prevalence of foodborne pathogens, and generic E. coli in soil and produce. The web-base platform will be finalized and made accessible to the participant farmers. We plan to submit three manuscripts for publication. Activity 2 (experimental field trials): We plan finalize data analyses of the 3 field trials, as state-level and multi-regional, and for publication. Activity 3 (Outreach and Extension) fact sheet was developed to accompany the outreach modules to encourage other educators to use the materials and extend the reach of these outreach resources. It can be viewed at https://producesafetyalliance.cornell.edu/sites/producesafetyalliance.cornell.edu/files/shared/documents/FSMA-PSR-Documentation-Requirements-for-Commercial-Soil-Amendment-Suppliers.pdf. Once the two educational outreach modules are completed and have been reviewed by the other collaborators on this project, both modules will be posted on the project website as well as the Produce Safety Alliance website and related social media accounts for public use as PSA Trainer Resources. Additionally, the modules will be linked to the Food Safety Resource Clearinghouse, a widely-referenced source of curated, publicly-available food safety resources. The two outreach modules will be presented in 2021 via two webinars through The Organic Center and the Produce Safety Alliance. The webinars presented through the Produce Safety Alliance will be presented during the monthly PSA Educator's calls, and will highlight the developed modules as supplemental resources for food safety educators. The PSA Educator's listserv reaches 440 individuals. In addition, the recorded webinars will be listed on the PSA website and available to the public. The webinar presented through The Organic Center will target organic growers who will directly benefit from the produce safety and soil health information in the outreach modules.

Impacts
What was accomplished under these goals? Observed soil prevalence was 0.04% (1/2460) for E. coli O157, 7.3% (179/2460) for non-O157 STEC, 1.1% (26/2460) for Salmonella and 5.0% (122/2460) for L. monocytogenes during this 2-year study with samples from 0-180-dpa. For all 3 pathogen groups analyzed, prevalence peaked significantly just after manure application and decreased significantly by 30-dpa and onwards. A second peak for non-O157 STEC was observed after 120 dpa. Generic E. coli (gEc) in the soil, year, sampling day, season and presence of pathogens in manure samples were significant predictors of pathogens in the soil. Environmental factors (temperature, and precipitation) and soil factors (moisture, organic matter and micronutrients) were associated with pathogen prevalence. Animal manure type showed moderate evidence of association with pathogen prevalence. Soil samples amended with cattle or horse manure had lower concentrations of gEc compared to poultry manure. Environmental factors (humidity, precipitation, temperature and snow) and soil factors (micronutrients and organic matter) were associated with higher counts of gEc. This preliminary analysis provides science-based information to identify potential risk factors influencing foodborne pathogen persistence in pre-harvest produce production environments for soils amended with raw manure on organic production systems. Activity 2: Preliminary statistical analyses were conducted for the CA and MD field trials. A randomized complete block study was conducted on NOP-certified plots during 2017-2018 in California, Minnesota and Maryland. Survival of generic E. colirif-R (EC) on soil, tomatoes, radish/carrots and spinach was determined over 90-120(-180)-days for dairy manure (DM), horse manure (HM), poultry litter (PL), and unamended (UnA) plots. California Trials: E. coli persisted in all HM, DM, PL, and UA plot soils growing carrot, spinach and tomato through 180 dpaEC survival in manured soil and transfer to crops. Reliance on wait-time intervals alone needs further evaluation.

Publications

  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2020 Citation: Pires A*, Ramos T, Millner P, Stover J, Pagliari P, Hutchinson M, Liley J, Rowley N, Aminabadi P, Baron J, Kenney A, Hashem F, Jay-Russel M. Risk factors associated with Escherichia coli persistence in soils amended with raw manure in certified organic farming systems in four regions of USA (P3-145) 2020 Annual IAFP Meeting, Virtual Meeting, October 26-28, 2020.(Poster Accepted, *presenter).
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2020 Citation: Pires A*, Ramos T, Millner P, Stover J, Pagliari P, Hutchinson M, Liley J, Rowley N, Aminabadi P, Baron J, Kenney A, Hashem F, Jay-Russel M. Risk factors associated with prevalence of foodborne pathogens in manured soils from USDA-NOP-certified organic farms in four regions of USA. (T3-04). 2020 Annual IAFP Meeting, Virtual Meeting, October 26-28, 2020. (Oral Presentation Accepted *presenter)
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2020 Citation: Aminabadi P*, Pires A, Millner P, Zwieniecka A, Ramos T, Jay-Russell. M. 2020. Transfer of indicator Escherichia coli to spinach, carrots and tomatoes grown in organic soil amended with raw animal manure in California, 2018-2019 (P3-150). 2020 Annual IAFP Meeting, Virtual Meeting, October 26-28, 2020.(Poster Accepted *presenter)
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2020 Citation: Kenney A*, Hashem F, Pires A, Jay-Russell M, Millner P, Collick, A. 2020. Precipitation and soil moisture effects on survival and transfer of Escherichia coli to fresh produce in manure-amended certified organic, (P3-74). Annual 2020 Annual IAFP (International Association for Food Protection) Meeting, Virtual Meeting, October 26-28, 2020. (Poster Accepted *presenter)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: AL Kenney*, FM Hashem, P Millner, A Pires, M Jay-Russell. Assessing Escherichia coli Survival in Manure-Amended Certified Organic Soils and Transfer to Tomatoes, Radish, and Spinach Grown on the Eastern Shore of Maryland. Poster # 1321. ASA-CSSA-SSSA International Annual Meetings (2019). November 10-13, 2019 (Poster* Presenter)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Clements D, Bihn EA*. Using organic soil amendments to build soil health and enhance food safety. New England Vegetable and Fruit Conference, December 11, 2019. (Oral *presenter)
  • Type: Theses/Dissertations Status: Published Year Published: 2019 Citation: AL Kenney*. Master of Science Thesis: Assessing Escherichia coli Survival in Manure-Amended Certified Organic Soils Cultivated with Tomatoes, Radish, and Spinach on the Eastern Shore of Maryland. Assessing Escherichia coli Survival in Manure-Amended Certified Organic Soils Cultivated with Tomatoes, Radish, and Spinach on the Eastern Shore of Maryland. December 2019


Progress 09/01/18 to 08/31/19

Outputs
Target Audience:The target audiences reached include various stakeholders in organic agriculture and produce food safety, including organic farmers, researchers, extension specialists, extension agents, policy makers, experts and industry working in organic agriculture. They were reached as part of the conferences, workshops and informal education activities (field days, one -to-one meetings with farmers) delivered through presentations at national and international meetings and conferences. In particular, many stakeholders were exposed to our research findings at the: 1) 2019 To reach our target audience the Organic Center disseminated a press release to publicize the planned research. The Organic Center also developed a web portal where a description of the project, updates, and information has been posted. We also launched and maintain a social media campaign surrounding the research via The Organic Center and Organic Trade Association Facebook and Twitter accounts, and a unique Twitter account developed specifically for this project. The combined reach of our organizations' social media pages is over 151,564 individuals for Facebook, and over 69,900 followers for Twitter. Changes/Problems:The research team is working to identify a new economist to collaborate in this project. What opportunities for training and professional development has the project provided?The project provided support for graduate/post-doctoral and undergraduate research, thus helping to build capacity for future professionals in microbiology, epidemiology and food safety. Dr. Pires mentored one Postdoctoral researcher, one PhD student, 2 junior specialists and 5 undergraduate students at UC Davis. Drs. Millner, Hashem and Piresco-mentored one master student enrolled at UMES. How have the results been disseminated to communities of interest?The results have been disseminated through outreach activities involving organic farmers, researchers, extension specialists, extension agents, policy makers, experts and industry working in organic agriculture. They were reached as part field days, one-to-one interactions, workshops and informal education activities delivered through presentations at national and international meetings and conferences. In particular, many stakeholders were exposed to our research findings at national and international conferences and regional meetings. Activity 3: We are communicating our accomplishments to communities of interest using a variety of techniques. We pushed out a press release about the project, which can be found on 214 websites, with a potential total audience of 11,804,269 unique visitors per day.The total potential audience from tweets of the press release is 30,976 followers. Additionally, we are communicating with the public through a website which includes a description of the project and updates with pictures from the field. We have also leveraged the project outreach with the Organic Center's Google Ad Words Grant, which provides up to $40,000 of funding per month for Google Ad Words. This campaign has generated a total of 261,903 clicks and 2,868,609 ad views over the last year. We are using social media to ensure that we reach a wide variety of stakeholders via the Organic Center and Organic Trade Association social media pages. The combined Twitter following for these organizations is 69,900 and the Facebook following is 151,564. The project has also been communicated through in-person meetings with industry and farmer partners. For example, it was featured at the Organic Confluences Conference, which focuses on collaborative solutions to organic sector challenges. Finally, the project has been publicized in several Newsletters, including the Organic Center Scoop, which goes out to 23,689 individuals, and the Organic Trade Association Newsflash, which goes out to 3,500 subscribers. The project was also publicized in the Organic Report, a magazine with a readership of over 21,000. Dr. Michele Jay-Russell (WCFS UC Davis), in her role as Manager of the Western Center of Food Safety, an FDA Center of Excellence at UC Davis, Dr. Jay-Russell communicates directly with FDA CFSAN partners in the divisions of Produce Safety, Whole Genome Sequencing, and Risk Assessment. This OREI project is complementary to other BSAAO-related research funded by FDA, and data sharing is encouraged with industry and regulatory stakeholders, especially as it relates to implementation of the FSMA Produce Safety Rule and development of a risk assessment for raw animal manure. What do you plan to do during the next reporting period to accomplish the goals?Activity 1: During this 3- year period were able to assess the the survival rate of generic E. coli and foodborne pathogens (Salmonella, STEC and L. monocytogenes) in soil amemeded with raw manure in a longitudinal multi-regional study in three regions. Descriptive statistical analysis was conducted to evaluate regional, temporal and management practice effects on the prevalence and survival of foodborne pathogens in manure and soil. Of 233 manure and compost samples, a total of 40 (17.2%) samples were positive to at least one of the pathogens we tested forRisk factor analysis and predictive modeling approaches will be conducted to evaluate management and environmental effects on survival of foodborne pathogens. A pilot of the online platform for data visualization was tested and customized self-risk assessment tool will be make available to the participant farmers. Activity 2 (Field trials, Objective 2): A randomized complete block study was conducted on NOP-certified plots during 2017-2018 in California, Minnesota and Maryland. Survival of generic E. colirif-R (EC) on soil, tomatoes, radish/carrots, and spinach was determined over 90-120(-180)-days for dairy manure (DM), horse manure (HM), poultry litter (PL), and unamended (UnA) plots. Maryland Trials: All soil treatments were 100% positive for EC (5.85 logMPN/g) after inoculation. Temperature, growing degree days (GDD), and precipitation during 120-day spinach and radish crop trials in 2017 and 2018 were distinctive. Mean temperature was 8?C higher in 2018 than in 2017. Total precipitation was significantly (p<0.5) greater during 2018 (~56cm) than in 2017 (~26cm). GDD during 2018 (GDD = but by 120-day 30-40% were positive in DM and PL 2017, respectively. In 2018, EC declined to 10-20% by 90&120-day with no transfer to tomato fruits. However, EC in soil varied substantially during 2017 spinach growing season, with all harvested leaves were EC positive. California Trials: Horse manure (HM), dairy manure solids (DMS) and chicken litter (CL) were tilled separately into four replicate soil plots (4×1 m) at a UC-Davis NOP certified research field in October 2018 (Field Trial, Year 2). Plots were inoculated with rifampicin-resistant indicator Escherichia coli (E. colirif) at 108 MPN/g. Controls included un-amended (UA) and un-inoculated (UI) plots. Organic spinach and carrot seeds were planted 7-days post application (dpa), and tomato seedlings transplanted 14-dpa. E. colirif was quantified from soil and plant samples by direct plating and MPN. E. coli persisted in all HM, DMS, CL, and UA plot soils growing carrot, spinach and tomato through 180 dpa (means, 2.9×103, 3.2×102 and 1.7×100 MPN/g respectively). E. colirif enumerated from spinach leaves (mean 2.4×103 MPN/g) as well as carrots (mean 8.3×101 MPN/g) grown in manure-amended and UA plots were insignificantly different (P>0.05). E. colirif was isolated once from tomatoes (133 dpa) on an HM plot (2×10-2 MPN/g). For the next report, we will analyze data from the 2017-2019 for Minnesota field trials. Additionally, by that time we will have more analysis comparing results from the different field trials across growing seasons and regions. The Activity 3 (Outreach and Extension): The Organic Center and regional collaborators will continue with the outreach activities described above by enganging a diverse audience through the use of multiple information outletsOutreach modules are being developed to inform farmers using biological soil amendments, including organic farmers, about the relationship between soil health, food safety, and use of soil amendments such as compost and manure. These outreach modules are incorporating results from this project and will be publically available to download from the Produce Safety Alliance website foruse in extension and outreach programs. The development of thse resources will be highlighted on the Produce Safety Alliance' and The Organic Center's social media pages. Additionally, these modules will be presented in year 4 via two webinars through The Organic Center and the Produce Safety Alliance, and in person at two grower conferences. A fact sheet is being developed to to accompany the outreach modules to encourage other educators to use the materials and extend the reach of these outreach resources.

Impacts
What was accomplished under these goals? Prelyminary data regarding manure and soil findings of year 2 (2018-2019) were reported in previous report. Descriptive statistics of years 1-2are described in this report. Soil microbial population assessment is pending. Activity 2: In 2018, three certified organic centers (one in each region) were selected for the field trials. CA: research plots at certified organic field at the University of California, Davis; MN: Southwest Research and Outreach Center (SWROC), Lamberton MN; and MD: University of Maryland Eastern Shore Research Farm, MD. At each center randomized complete block design was conducted. A randomized complete block design with 4 replications for each of 4 treatments: horse manure, dairy manure, poultry litter and unamended (UnA), were established at the at each research site.The organic soils amended with raw animal manure and unamended soils were inoculated with a three-strain cocktail of non-pathogenic, rifampicin-resistant E. coli (ECrif-R) at 6 log CFU/ml (1-L per 2m2 plot). Soils were analyzed on days pre- and post-inoculation (0-180 days). Transfer of EC to produce was determined at 90 and 120 days post-application of manure and EC inoculum. Crops of interest were: spinach, carrots, tomatoes and radishes.

Publications

  • Type: Journal Articles Status: Published Year Published: 2019 Citation: De Melo Ramos T, Jay-Russell M, Millner PD, Shade J, Sorge US, Hutchinson M, Lilley J, Pires AFA. Assessment of organic produce farming research and outreach needs regarding food safety risks and raw manure and compost applications Front. Sustain. Food Syst. 3:73. doi: 10.3389/fsufs.2019.00073 (related work).
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Rowely N*, Hutchinson M, Lilley J, Pires A, Ramos T, Stover J, Jay-Russel M, Pagliari P, Millner P, J, Hashem F. 2019. Tracking Potential Human Pathogens in Organic Vegetable Systems After Pre-Plant Manure Application, The Northeastern Plant, Pest, and Soils Conference 2019, Hunt Valley, MD, January 8-10, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Aminabadi P*, Pires A, Millner P, Zwieniecka A, Ramos T, Jay-Russell. M. 2019. Transfer of Indicator Escherichia coli to Spinach and Carrots Grown in Organic Soil Amended with Raw Animal Manure in California, (P2-180) International Association for Food Protection (IAFP) Annual IAFP Meeting 2019, Louisville, KT, July 21-24.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Kenney A*, Hashem F, Pires A, Jay-Russell M, Millner P. 2019. Evaluating the Fate of Escherichia coli in Manure-Amended Certified Organic Soils and Transfer to Field-grown Tomatoes, Radish, and Spinach in Maryland Eastern Shore, (P2-230) International Association for Food Protection (IAFP) Annual IAFP Meeting 2019, Louisville, KT, July 21-24.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Ramos T, Jay-Russel M, Millner P, Stover J, Pagliari P, Hutchinson M, Liley J, Rowley N, Aminabadi P, Baron J, Kenney A, Hashem F, Pires A*. 2019. A multi-regional study of generic Escherichia coli persistence in soils amended with raw manure and produce in organic farming systems (P2-188) International Association for Food Protection (IAFP) Annual IAFP Meeting 2019, Louisville, KT, July 21-24.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Ramos T, Jay-Russel M, Millner P, Stover J, Pagliari P, Hutchinson M, Liley J, Rowley N, Aminabadi P, Baron J, Kenney A, Hashem F, Pires A*. 2019. Multi-regional prevalence and persistence of four foodborne pathogens in manured soils in certified organic farms, (P2-189) International Association for Food Protection (IAFP) Annual IAFP Meeting 2019, Louisville, KT, July 21-24. Poster presentation.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Pires A, Jay-Russell M. Foodborne Pathogen Prevalence and Risk Factors on Small-Scale, Organic and Biodiversified Farms in California: Implications for Food Safety and Agritourism (1894). Public and Corporate Practice|| Dr. James H. Steele One Health Workshop. Invited Speaker. 2019 AVMA Convention, Washington D.C., August 2-6, 2019.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Pires A, Jay-Russell M. Panel Discussion: Foodborne Pathogen Risk Factors on Small-Scale and Organic Livestock Farms: Science, Policy and Legal Prespectives (3103). Public and Corporate Practice|| Dr. James H. Steele One Health Workshop. Invited Speaker. 2019 AVMA Convention, Washington D.C., August 2-6, 2019.


Progress 09/01/17 to 08/31/18

Outputs
Target Audience:The target audiences reached include various stakeholders in organic agriculture and produce food safety, including organic farmers, researchers, extension specialists, extension agents, policy makers, experts and industry working in organic agriculture. They were reached as part of the conferences, workshops and informal education activities (field days, one -to-one meetings with farmers) delivered through presentations at national and international meetings and conferences. In particular, many stakeholders were exposed to our research findings at the:1) 2018, The Second 1890 ARD & USDA-ARS Food Safety Consortium Symposium, April 23-35, 2018;USDA-ARS-Beltsville Agricultural Research Center, Beltsville, MD;2) 2018, Western Regional Center to Enhance Food Safety -2ndAnnual Meeting, March 27-28, UC Davis Conference Center, Davis, CA; 3) 2018International Association for Food Protection 2018 Annual Meeting (IAFP), July 8-11, 2018, Salt Lake City, UT ;4) 2018FSMA Produce Safety Rule Training for California Specialty Crop Growers.University of California, School of Veterinary Medicine UC Davis, February 21, 2018, Davis, CA; 5)2018 Center for Food Animal Health (CFAH) 2018 Stakeholder Workgroup Advisory Meeting, UC Davis, February 24, 2018, Davis, CA. In 2018, a total of seventeen certified organic farms were enrolled in the longitudinal multi-regional study in three growing regions (West: 9 California; Midwest: 4 Minnesota; and East: 4 Maine, 1 Maryland) and sampled. Organically certified farms were surveyed (monthly visits) and cooperated in farm survey from February - December, 2018 (Activity 1, farm survey study).In 2018, three certified organic centers/sites (one in each region) were selected for the experimental field trials. California: organic research farm at the University of California, Davis; Minnesota:SouthwestResearchandOutreachCenter(SWROC), Lamberton MN; and Maryland:University of Maryland Eastern Shore Research FarmMD(Activity 2, field trials). To reach our target audience the Organic Center disseminated a press releases to publicize the planned research. The Organic Center also developed a web portal where a description of the project, updates, and information has been posted. We also launched and maintain a social media campaign surrounding the research via The Organic Center and Organic Trade Association Facebook and Twitter accounts, and a unique Twitter account developed specifically for this project.The combined reach of our organizations' social media pages is over 130,000 individuals for Facebook, and over 40,000 followers for Twitter. The experimental field trials located at the SWROC were featured during our 2018 Organic Field Day. Over 30 organic farmers attended the event to learn about the new research on organic farming that is underway at the SWROC. Every year the event has a morning field tour where the attendees ride along a wagon to visit selected research sites. And in 2018, this field trials were one of the highlieghted locations visited. Changes/Problems:In the second year, enrollement was expanded to include rotational grazing and expand geographical areas: 3 new farms were enrolled ( 1 CA, 1MN and 1 ME). The number of samples per farm were increased to reflect the type of manure and produce grown. Note: In this report, we are presenting preliminary data from the year 2 corresponding to the growing season and sampling from February 2018 to December of 2018. What opportunities for training and professional development has the project provided?The project provided support for graduate/post-doctoral and undergraduate research, thus helping to build capacity for future professionals in microbiology, epidemiology and food safety.Dr. Pires mentored one Postdoctoral researcher, one PhD student, 2 junior specialists and 5 undergraduate students at UC Davis. Drs. Millner and Hashemco-mentored one master student. How have the results been disseminated to communities of interest?The results have been disseminated through outreach activities involvingorganic farmers, researchers, extension specialists, extension agents, policy makers, experts and industry working in organic agriculture. They were reached as part field days, one-to-one interactions, workshops and informal education activities delivered through presentations at national and international meetings and conferences. In particular, many stakeholders were exposed to our research findings at the: 1) 2018, The Second 1890 ARD & USDA-ARS Food Safety Consortium Symposium, April 23-35, 2018;USDA-ARS-Beltsville Agricultural Research Center, Beltsville, MD; 2) 2018, Western Regional Center to Enhance Food Safety -2ndAnnual Meeting, March 27-28, UC Davis Conference Center, Davis, CA. 3) 2018International Association for Food Protection 2018 Annual Meeting (IAFP), July 8-11, 2018, Salt Lake City, UT; 4) 2018. FSMA Produce Safety Rule Training for California Specialty Crop Growers.University of California, School of Veterinary Medicine UC Davis, February 21, 2018, Davis, CA; 5) 2018 Center for Food Animal Health (CFAH) 2018 Stakeholder Workgroup Advisory Meeting, UC Davis, February 24, 2018, Davis, CA. Activity 3: We are communicating our accomplishments to communities of interest using a variety of techniques.We pushed out a press release about the project, which can be found on 214 websites, with a potential total audience of 11,804,269 unique visitors per day.The total potential audience from tweets of the press release is 30,976 followers.Additionally, we are communicating with the public through a website which includes a description of the project and updates with pictures from the field. We have also leveraged the project outreach with the Organic Center's Google Ad Words Grant, which provides up to $40,000 of funding per month for Google Ad Words.This campaign has generated a total of 279,127 clicks and 96,110,327 ad views over the last year.We are using social media to ensure that we reach a wide variety of stakeholders via the Organic Center and Organic Trade Association social media pages.The combined Twitter following for these organizations is 59,156 and the Facebook following is 151,765.Finally, the project has been publicized in several Newsletters, including the Organic Center Scoop, which goes out to 23,689 individuals, and the Organic Trade Association Newsflash, which goes out to 3,500 subscribers.The project was also publicized in the Organic Report, a magazine with a readership of over 21,000. Dr. Michele Jay-Russell (WCFS UC Davis), in her role as Manager of the Western Center of Food Safety, an FDA Center of Excellence at UC Davis, Dr. Jay-Russell communicates directly with FDA CFSAN partners in the divisions of Produce Safety, Whole Genome Sequencing, and Risk Assessment. This OREI project is complementary to other BSAAO-related research funded by FDA, and data sharing is encouraged with industry and regulatory stakeholders, especially as it relates to implementation of the FSMA Produce Safety Rule and development of a risk assessment for raw animal manure. What do you plan to do during the next reporting period to accomplish the goals?The Activity 1 (Longitudinal study and farm survey) of year 2 is completed with enrollment of seventeen certified organic farms were enrolled in the longitudinal multi-regional study in three regions.The farms were geographically spaced in diferents regions (Midwest: Southeast and East Minnesota and West Wisconsin; West: Central Coast, Central Valley, North Coast and Southern California; East Coast) to represent different growing climates including soil type and weather patterns and agricultural practices.These are small diversified farms growing many different crops (including kale, carrots, tomatos, radishes, lettuce, cucumbers, peppers, melons, beets and potatos) in small spaces. The number of crops per farm ranged from 1 to 4 types.This second year were able to assess the the survival rate of genericE. coliand foodborne pathogens in soil amemeded with raw manure.Weather, environmental data and farm -management data were collected during the study period.Statistical analysis will be conducted to determine the association between on-farm management factors, manure factors, soil factors (health and level of contamination), environmental factors and landscape on fresh produce in each of the following outcomes of interest: 1) the prevalence of pathogens (Salmonella, STEC andL. monocytogenes) in soil and produce;and 2) levels of microbial contamination indicators (i.e., genericEscherichia coli) in soil and produce. A customized self-risk assessment tool, based on a on-farm demographics and management practices, meteorological and environmental information will be developed and make available to the participant farmers.Microbial diversity is also being assessed for organic farm sites as well. Samples for soil health assessment were sent to University of Maine at the end of each season and data will be analyzed for associations with soil amendment treatment effects and microbial community analyses. The Activity 2 (Field trials, Objective 2):Because spinach and carrots are winter crops in Davis California, our second field trails extended into year 3. For the next report, we will analyze data from the 2018-2019 leafy greens and carrot trials. Additionally, by that time we will have more analysis comparing results from the 2 different field trials across growing seasons. Statistical analyses will be conducted for all three field trial sites. The Activity 3:The Organic Center and regional collaborators will continue with the outreach activities described before, byenganging a diverse audience in outreach and using different information outlets. During the year 3 and 4,farmer-focused outreach and extension effortsaimed directly at organic farmers through the development and presentation of a webinar, continuing education modules and fact sheets for organic growers.

Impacts
What was accomplished under these goals? Activity 1:In 2018, a total of 17 certified organic farms were enrolled in the longitudinal multi-regional study in three growing regions (West: 9 CA; Midwest: 4 MN; and East: 4 ME, 1 MD). Farms were surveyed (monthly visits, 8 total ) and cooperated in farm survey from Feb-Dec 2018. Manure (cattle, poultry, horse and small ruminants), soil, irrigation water and produce (leafy greens, tomatos, peppers, radishes, cucumbers, melons, carrots, beets) were collected for a period of 7 to 8 months Soil samples were analyzed for composition, soil health and microbial populations.The presence of 4 foodborne pathogens (non-O157 Shiga toxin-producingEscherichia coli(STEC),E. coliO157:H7,Listeria monocytogenesandSalmonella) and contamination indicators (genericE. coli) were assessed in manure, soil, irrigation water and produce. Most Probable Number (MPN) methods were used to quantify genericE. coliand confirmed via PCR insoil samples, water and fresh produce. Overall, 53.7% of samples were positive forE. coli(755/1360): 60.3% soil and, 22.5% produce, and 23.7% water. Average MPN values were: in CA, 0.60 log MPN/100g dryfor soil,0.11 log MPN/100g for produce. In MD, 1.06 log MPN/100gfor soil, 0.14 log MPN/100gfor produce. In ME, 0.55 log MPN/100g for soil (range 0 - 4.94), 0.40 log MPN/100g for produce. In MN, 1.19 log MPN/100g for soil, 0.23 log MPN/100g for produce. Populations of genericE. colidecreased substantially by 120 days post manuring on 10 of 17 farms. Samples were cultured for STEC,E. coliO157:H7,Listeria monocytogenesandSalmonella. Manure samples were positive for non-O157 STEC (7.9%, 18/228),E. coliO157:H7 (1.32%, 3/228) andL. monocytogenes(3.9%, 9/228). The prevalence of non-O157 STEC in soil samples was 10.4% (73/700), 7.7% (80/1043), 5.2% (10/196), and 4.1% (16/386), in MN, CA, MD, and ME, respectively.L. monocytogeneswas detected in 7.3% (31/700), 5.5% (47/1043), 4.4% (25/196), and 4.2% (1/196) of soil samples from MN, CA, ME and MD, respectively.Salmonellawas detected in 1.1% (26/2295) of soil samples. Non-O157STEC andL. monocytogeneswere detected in soil up to 30 and 90 days post-manuring, respectively. All water samples were negative for foodborne pathogens (0/38). Produce results are pending. Soil health and compositon were evaluated. Farm-management practices, environment factors (weather and temperature/ soil moinsture) were recorded. Soil microbial population assessment is pending. Activity 2:In 2018, three certified organic centers (one in each region) were selected for the field trials. CA: research plots at certified organic field at the University of California, Davis; MN:SouthwestResearchandOutreachCenter(SWROC), Lamberton MN; and MD:University of Maryland Eastern Shore Research Farm, MD. At each center randomized complete block design was conducted.A randomized complete block design with 4 replications for each of 4 treatments: horse manure (HM), dairy manure (DM), poultry litter (PL) and unamended (UnA), were established at the at each research site.The organic soils amended with raw animal manure and unamended soils were inoculatedwith a three-strain cocktail of non-pathogenic, rifampicin-resistantE. coli (ECrif-R)at 6 log CFU/ml (1-L per 2m2plot). Soils were analyzed on days pre- and post-inoculation (0-180 days).Transfer of EC to produce was determined at 90 and 120 days post-application of manure and ECinoculum. In 2017-2018, at MD site, certified-NOP silty-loam field-plots were amended DM or HM, PL, or UnA, before spray-inoculating with a mixture of rifampicin-resistantE. coli(ECrif-R) at 6 log CFU/mL. Composite-core samples were enumerated(MPN) on 0, 30, 60, 90, 120-dpi, with harvested produce enrichments on 90 and 120-dpi. In radish soils, ECrif-Rpopulations declined from 100% positive (n=32) on 0-dpi to 0-20% positive for all treatments by 90-120-dpi (n=64), but 100% persistence on bulbs for all 2017 treatments; 2018 PL and DM-amendments supported 50% positive (n=16) transfer of ECrif-Rto 120-dpi bulbs. For tomato soils, ECrif-Rpopulations at 100% positive (n=32), 0-dpi (2017, 2018) declined to 20% for all manured treatments by 90-dpi, but 30% and 40% were positive by 120-dpi in DM and PL 2017 plots respectively; army worm-frass resulted in 100% contamination of all tomato fruits (n=32). In 2018, ECrif-Rdeclined to 10-20% by 90-120-dpi with no transfer to tomato fruits. Spinach soil ECrif-Rpopulations varied substantially during 2017-2018 with 100% transfer to harvested 30-g samples/plot, (n=32) in 2017; the 2018 crop failed. At the MN site located at the SWROC, the crops grown were tomoatoes, spanich and radish. All crops grew well and soil and produce samples were collectedand analyzed according to the research plan. The transfer and enumeration of survivingE. colionto the harvested tomatoes and radishes was assayed. In addition, to determining the survival of the inoculatedECrif-Rcocktail samples, n=48 every 4-weeks, were collected and shipped to USDA-ARS in Beltsville, MD, from all field plots comprising manure amendment treatments (DM, HM, PL and UnA). Upon arrival, subsamples were analyzed directly for survivingE. coli. In addition, and a subsample was frozen at -80oC for subsequent assay of microbial community diversity; these assays are still in progress for years 2017 and 2018. CA, winter crops (2017-2018): The first leafy greens (spinach) and root crop (carrot) field trials were initiated in 2017 (fall) and completed in 2018 (spring) at the UC Davis certified organic research farm.Chicken litter (CL), dairy manure solids (DMS), and horse manure (HM) were tilled separately into four replicate soil plots. Plots were inoculated with a three-strain cocktail of rifampicin-resistantE. coli(108MPN/g). Controls included un-amended (UA) and un-inoculated (UI) plots. Organic spinach and carrot seeds were planted 12 days post-application (dpa). Soil samples were collected from 0-180-dpa. Spinach leaves and carrots were harvested on 98-/131- and 127-/168-dpa, respectively.E. colipopulations were quantified using direct plating and Most Probable Number (MPN) methods.E. colipersisted in soil from all manure-amended plots through 180-dpa. Manure and crop type influencedE. colisurvival. In the spinach field, DMS-amended soil had significantly higherE. colicounts compared with UA- and HM-amended plots (p-value<0.05). In contrast, counts were significantly higher in soil from HM- compared with CL- and DMS-amended plots in the carrot field (p-value<0.05). Transfer of inoculum to spinach leaves was observed on 98-dpa (average, 0.9 x 10 MPN/g) and 131-dpa (average, 0.01 x 10 MPN/g). Carrot samples were positive at 127-dpa (average, 1.5×102MPN/g) and 168-dpa (average, 1.6×102MPN/g). The second winter field trials (spinach and carrots) are underway and will be completed in Spring 2019. CA Summer Crops (2018): The second tomato field trial was conducted during the 2018 growing season (spring-summer). CL,DMS, and HM were inoculated as described above in May 2018. Controls included UA and UI plots. Each plot was sampled and analyzed for inoculum concentration using most probable number (MPN) and direct plating (CFU) in the following 0, 1, 3, 7, 14, 28, 56, 90, 120, 150 and 180 dpa. Drip irrigation was setup followed by covering the plots with white plastic mulch then organic red Brandywine tomatoes were transplanted on 14-dpa.E. colipersisted in soil from all manure-amended and the unamended plots through 180-dpa with the average of 1.2 MPN/g. Tomato fruits were harvested on 120, 133 and 153-dpi. On day 133 one tomato bag collected form a HM plot tested positive for low levels of rif-resistanceE. colitransfer (3×10-4MPN/g) to the fruits.Preliminary findings from field trials in CA suggest thatE. coliin manure-amended soil may persist and be transferred to leafy greens and root crops in organic production.

Publications

  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Pires AFA, Millner PD, Baron J, Jay-Russell M. 2018. Assessment of Current Practices of Organic Farmers Regarding Biological Soil Amendments of Animal Origin in a Multi-Regional US Study. Food Protect. Trends 2018. 38 (5) 347-362. (Sinergetic activities/Products)
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Aminabadi P, Patterson L, Pires A, Millner P, Jay-Russell. M. 2018. Field validation of minimum application intervals for raw animal manure used as a soil amendment at a certified organic research farm in California, (Abstract P1-182) Annual IAFP Meeting 2018, Salt Lake City, UT, July 8-11.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Kenney A, Millner P, Pires A, Jay-Russell M, Hashem F. 2018. Survival of E. coli in Manure-amended Certified Organic Soils and Transfer to Tomatoes, Radish, and Spinach in Maryland Eastern Shore, American Society for Horticultural Science (ASHS 2018), Washington D.C., July 30-August 3.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Kenney A, Hashem F, Pires A, Jay-Russell M, Millner P. 2018. Survival of Escherichia coli in manure-amended soils and transfer to tomato, radish, and spinach on a Maryland certified organic farm (Abstract P1-139) Annual IAFP Meeting 2018, Salt Lake City, UT, July 8-11.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Ramos T, Jay-Russel M, Millner P, Stover J, Pagliari P, Hutchinson M, Liley J, Hashem F, Pires A. 2018. Multi-regional risk analysis of manure use: survival and persistence of foodborne pathogens in soil and contamination risk of fresh produce in certified organic farms, (Abstract T3-01) Annual IAFP Meeting 2018, Salt Lake City, UT, July 8-11.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Ramos T, Jay-Russel M, Millner P, Stover J, Pagliari P, Hutchinson M, Liley J, Hashem F, Pires A. 2018. A multi-regional risk analysis of raw manure soil amendment use on certified organic farms: survival of generic Escherichia coli in soil and produce (Abstract T3-03) Annual IAFP Meeting 2018, Salt Lake City, UT, July 8-11.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Kenney A*, Hashem F, Pires A, Jay-Russell M, Millner P. Survival and persistence of non-pathogenic of E. coli in Manure-Amended certified organic soils and transfer to tomato, radish, and spinach grown on eastern shore of Maryland. The Second 1890 ARD & USDA-ARS Food Safety Consortium Symposium, April 23-35, 2018; USDA-ARS-Beltsville Agricultural Research Center, Beltsville, MD
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Pires A, Multi-regional risk analysis of farm manure use for organic fresh produce: an integrative approach In Presentations of Successful Cooperative Projects Session. The Second 1890 ARD & USDA-ARS Food Safety Consortium Symposium, April 23-35, 2018; USDA-ARS-Beltsville Agricultural Research Center, Beltsville, MD
  • Type: Other Status: Other Year Published: 2018 Citation: Pires, A, February 21, 2018. FSMA Produce Safety Rule Training for California Specialty Crop Growers. Organizer & Speaker. University of California, School of Veterinary Medicine UC Davis, February 21, 2018, Davis, CA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Jay-Russell M. Research Updates on Wildlife Co-Management/Soil Summit. Invited Speaker Western Regional Center to Enhance Food Safety (WRCFS):2nd Annual Meeting, March 27-28, 2018, UC Davis Conference Center, Davis, CA
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Pires A, Research Updates on Soil Amendments Soil Summit. Invited Speaker Western Regional Center to Enhance Food Safety (WRCFS):2nd Annual Meeting, March 27-28, 2018, UC Davis Conference Center, Davis, CA
  • Type: Other Status: Other Year Published: 2018 Citation: Pires, A, February 23, 2018. Food Safety: Research Updates. Invited Speaker. Center for Food Animal Health (CFAH) 2018 Stakeholder Workgroup Advisory Meeting, UC Davis, February 24, 2018, Davis, CA.


Progress 09/01/16 to 08/31/17

Outputs
Target Audience:The target audiences reached include various stakeholders in organic agriculture and produce food safety, including organic farmers, researchers, extension specialists, extension agents, policy makers, experts and industry working in organic agriculture. They were reached as part of the conferences, workshops and informal education activities (field days, one to one meetings with farmers) delivered through presentations at national and international meetings and conferences. In particular, many stakeholders were exposed to our research findings at the 1) 2017 Organic Confluences, Making Research Count, Washington, D.C. May 22-23, 2017; 2) International Association for Food Protection 2017 Annual Meeting (IAFP); Tampa, Florida July 9-12, 2017 and 3) Soil Summit 2017, Produce Safety Alliance & Institute for Food Safety at Cornell University. New York State Agricultural Experiment Station, Geneva, NY. March 28-29, 2017. In 2017, a total of sixteen certified organic farms were enrolled in the longitudinal multi-regional study in three growing regions (West: 8 California; Midwest: 3 Minnesota; and East: 4 Maine, 1 Maryland) and sampled. Organically certified farms were surveyed (monthly visits) and cooperated in farm survey from March - December, 2017 (Activity 1, farm survey study). In 2017, three certified organic centers/sites (one in each region) were selected for the experimental field trials. California: organic research farm at the University of California, Davis; Minnesota: Southwest Research and Outreach Center (SWROC), Lamberton MN; and Maryland: University of Maryland Eastern Shore Research Farm MD (Activity 2, field trials). Changes/Problems:In the first year, we weren't able to enroll 9 farms per region. Therefore to compensate the sample size in the overall study, we increased number of studied crops and type of manure per farm (e.g., number of samples within farm). In the second year of the study, we plan to expand the enrolment criteria (including rotational grazing) and geographic areas. What opportunities for training and professional development has the project provided?The project provided support for graduate/post-doctoral and undergraduate research, thus helping to build capacity for future professionals in microbiology, epidemiology and food safety. Dr. Pires mentored one Postdoctoral -researcher, one PhD student, 2 junior specialists and 4 udergraduate sutudents at UC Davis. Mark Hutchinson has mentored a master's student. How have the results been disseminated to communities of interest?The results have been disseminated through outreach activities involving organic farmers, researchers, extension specialists, extension agents, policy makers, experts and industry working in organic agriculture. They were reached as part field days, one-to-one interactions, workshops and informal education activities delivered through presentations at national and international meetings and conferences. In particular, many stakeholders were exposed to our research findings at the: 1) 2017 Organic Confluences, Making Research Count, Washington, D.C. May 22-23, 2017; 2) International Association for Food Protection 2017 Annual Meeting (IAFP); Tampa, Florida July 9-12, 2017, 3) Soil Summit 2017, Produce Safety Alliance & Institute for Food Safety at Cornell University. New York State Agricultural Experiment Station, Geneva, NY. March 28-29, 2017. What do you plan to do during the next reporting period to accomplish the goals?The second year (2017-2018) will include the year 2 of on-farm survey and field trials. Outreach and extension activies will be conducted as well.

Impacts
What was accomplished under these goals? Activity 1: Sixteen certified organic farms were enrolled in the longitudinal multi-regional study in three regions (8 California, 4 Maine, 3 Minnesota, and 1 Maryland) and sampled from March to December, 2017. Frequent farm visits (8 totall) were conducted throughout the growing season to collect manure, soil, water and produce samples. Samples were analyzed for a wide array of parameters, including nutrients, soil health quality and microbial populations. Manure (e.g., cattle, poultry, horse and small ruminants), soil, irrigation water and produce (e.g., leafy greens, tomtatos, peppers, radishes, cucumbers, melons) were collected for a period of 7 to 8 months. The presence and/or persistence of 4 foodborne pathogens (non-O157 Shiga toxin-producing Escherichia coli (STEC), E. coli O157:H7, Listeria monocytogenes and Salmonella) were assessed in manure, soil, irrigation water and produce (Objective 1.4.) and contamination indicators generic E. coli) in fresh produce (Objective 1.4.). Most Probable Number (MPN) methods were used to quantify generic E. coli soil samples (monthly), water and fresh produce (at harvest). Quantitative and qualitative recovery of E. coli in each sample was achieved via selective and differential culturing methods and confirmed via PCR. Overall, 55.6% of samples were positive for E. coli (755/1360): 55.5% soil and, 3.7% produce. Average MPN values were: in California, 1051 MPN/100g dry for soil (range 0 - 145,190), 15.6 MPN/100g for produce (range 0 - 123). In Maryland, 2,026 MPN/100g for soil (range 0 - 33,776), 11.5 MPN/100g for produce (range 0 - 22.5). In Maine, 1,220 MPN/100g for soil (range 0 - 87,736), 149.7 MPN/100g for produce (range 0 - 2,514). In Minnesota, 2,963 MPN/100g for soil (range 0 - 33,776), 885 MPN/100g for produce (range 0 - 15,750). The generic E. coli counts decreased considerably 120 days post manure application on 10 out of 16 farms. One irrigation water sample was generic E. coli positive. Samples were cultured for non-O157 Shiga toxin-producing Escherichia coli (STEC), E. coli O157:H7, Listeria monocytogenes and Salmonella. Manure samples were positive for non-O157 STEC (10.5%, 11/105), E. coli O157:H7 (0.95%, 1/105) and L. monocytogenes (6.7%, 7/105). The prevalence of non-O157 STEC in soil samples was 6% (6/100), 8.2% (15/196), 13.4% (48/358) and 13.9% (70/502) in MD, ME, MN and CA farms, respectively. L. monocytogenes was detected in 1% (1/100), 5.4% (27/502), 7.3% (26/358) and 12.8% (25/196) of soil samples in MD, CA, MN and ME, respectively. Salmonella was found in 0.5% (1/196) of soil samples in Maine. Non-O157 STEC and L. monocytogenes were detected in soil up to 180 days and Salmonella up to 120 days post-manure application. Only one produce sample was positive for L. monocytogenes. All water samples were negative for foodborne pathogens. Soil health and compositon parameters were evaluated (Objective 1.2). On farm-management practices, environment factors (weather and temperature/soil moinsture) were recorded (Objective 1.1.). Soil microbial population assessment is pending (Objective 1.3.) Individual farm reports with findings of year 1 were provided to each participant farm. Activity 2: In 2017, three certified organic centers/sites (one in each region) were selected for the experimental field trials. California: research plots at certified organic field at the University of California, Davis; Minnesota: Southwest Research and Outreach Center (SWROC), Lamberton MN; and Maryland: University of Maryland Eastern Shore Research Farm, MD (Activity 2, field trials). At each center/ site a randomized complete block design was conducted with 4 replications and amended with poultry litter, horse manure and dairy solids and unamended. The organic soils amended with raw animal manure and unamended soils were inoculated with a three-strain cocktail of non-pathogenic, rifampicin-resistant E. coli (rif-EC) at 6 log CFU/ml (1-L per 2m2 plot). A randomized complete block design with 4 replications for each of 4 treatments: horse manure (HM), dairy manure (DM), poultry litter (PL) and unamended (UnA), were established at the at each research site. Soils were analyzed on days 0, 7, 14, 28, 60, 90, and 120, 150, 189 pre- and post-inoculation. Transfer of EC to tomatoes, spinach, and radish was determined at 90 and 120 days post-application of manure and EC inoculum. Maryland: The EC survival was higher and more persistent in the PL-amended soils, than in any other treatment. In all tomato plots, yellow-striped army worms invaded and caused major crop damage by day 90, and were suspected of contributing to the large number of EC-positive tomato fruits when assayed. Spinach did not mature before frost set, and radishes from all treatments, except UnA, had surviving EC in the initial wash water of the bulbs. California: Organic heirloom tomatoes were transplanted in field plots (4 m2) amended with untreated dairy solids (DS), horse manure (HM), poultry litter (PL), and unamended controls (UA) at a certified organic farm in Davis. Soils at 90 dpi, had log reductions of rif-EC populations of 4.3 (DS), 5.1 (HM), 5.3 (PL) and 6.3 (UA); at 120 dpi, log reductions were 5.3 (DS), 5.8 (HM), 6.2 (PL) and 5.5 (UA). On the final sample day (180 dpi), the concentration of rif-EC (MPN/g) had decreased to 3.7 (DS), 18.0 (HM), 0.7 (PL), and 0.6 (UA). The inoculum was not detected in any tomato samples. Experiment day and rif-EC concentration (log MPN/g) were significantly associated (P< 0.001), but not manure type. Spinach results are pending. Minnesota field trails results are pending. Soil microbial community profile of the field trials is pending.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Pires A, Tocco P, Millner P. A Research Framework to Assess Pathogen Prevalence and Survival in Raw Manure Used in Produce Production in Biological Soil Amendments of Animal Origin and the Food Safety Modernization Act: Challenges and Opportunities Going Forward. International Association for Food Protection 2017 Annual Meeting (IAFP); Tampa, Florida July 9-12, 2017; Tampa, Florida July 9-12, 2017. (S27, Seminar).
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Pires A, Jay-Russell M. May 23, 2017. Integrative Research: Approaches in Organic Agriculture. Case Study3: Manure Safety Panel. Invited Speaker. 2017 Organic Confluences. Making Research Count, Washington, D.C. May 22-23, 2017.
  • Type: Other Status: Other Year Published: 2017 Citation: Pires A, Jay-Russell M. Soil Summit 2017, Produce Safety Alliance & Institute for Food Safety at Cornell University. Participant. New York State Agricultural Experiment Station, Geneva, NY. March 28-29, 2017.