Manure Irrigation: Airborne Pathogen Transport and Assessment of Technology Use in Wisconsin

This presentation will outline the completed research on manure irrigation pathogen transport including field data, transport models, and a quantitative microbial risk assessment.  Details will also be provided on the workgroup recommendations for use of this technology in Wisconsin.

Why Study Irrigation of Manure?  

Manure irrigation is of increasing interest to producers in Wisconsin as it allows for multiple application of manure throughout the growing season. This can reduce application costs while providing nutrients to a growing crop as opposed to a single manure application in the spring or fall. With increasing interest and potential for practice expansion many communities were concerned with the potential human health (pathogens), odor, and environmental issues associated with the practice.

What did we do?

The University of Wisconsin-Extension formed an 18 person workgroup representing many stakeholders and experts to review the practice of manure irrigation for impacts to odor, water quality, air quality, and human health among others. The workgroup developed recommendations for the practice which will be available in early May 2015 at In addition, a research team evaluated manure pathogen drift in the field to assess concentrations at increasing distance away from the source. These results were used to develop an air dispersion model as well as develop a quantitative risk assessment. These models and assessment were used to evaluated practice recommendations and to determine if there are reasonable setback distances which reduce risk to a level deemed acceptable by the workgroup.

What have we learned?        

There are a number of concerns and benefits that may be realized when using manure irrigation. There may be scenarios in which manure irrigation is a beneficial practice, but there may be locations in which it is not suitable due to sensitive environmental factors or proximity to neighbors. Like many manure system components management of the system is key, and if improperly manged can lead to negative impacts. Detailed recommendations of the workgroup will be available in May 2015.

Future Plans

The workgroup intends to complete the report by May 2015 to be made available to interested parties on the webpage. The research team is currently evaluating expanding the measurement of pathogens to other areas of the farm and additional land application techniques for comparison.


Dr. Becky Larson, University of Wisconsin,

Susan Spencer, Tucker Burch, Yifan Liang, Chris Choi

Additional information    


Wisconsin Department of Natural Resources and the USDA ARS in Marshfield, Wisconsin.

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