Evaluating Manure Nutrient Density and Paths for Improved Distribution

Increased density of livestock farms in some locations has increased manure nutrient density applied to the land base in that area. The increased nutrient density in some cases exceeds crop demands and leads to increased nutrient losses to the environment. In this study, we are using new approaches (including optimization modeling) to better inform stakeholders on locations which have excess manure nutrients produced as compared to crop uptake and pathways to improve distribution of manure nutrients including manure processing and transport options. The output of this work can be used to guide policy and development of methodologies to transport manure nutrients most cost effectively to improve nutrient distribution over a larger land-base area (such as a watershed).

What did we do?

We gathered data for livestock facilities in Wisconsin including location and production of manure to determine nutrient production as well as cropping information to determine nutrient uptake over a given land base. We then gathered information on several manure processing systems and used optimization models to identify the most cost effective methods of processing and transport to improve nutrient distribution.  

What have we learned?

We have found that some manure processing technologies are more economically viable than other technologies based on the desired environmental goal. In addition, we have begun to outline specific policy incentives that may be needed to begin to see increased installations of the manure processing systems modeled.  

Future plans

We plan to further investigate additional manure technologies, develop a website so others can integrate data into the models, and run additional scenarios to guide investments on manure processing systems. In addition, out next steps look to integrate life cycle assessment data into the optimization models for refinement of integration of environmental impacts.


Rebecca A. Larson, Associate Professor, Biological Systems Engineering, University of Wisconsin-Madison, rebecca.larson@wisc.edu

Horacio Aguirre-Villegas, Assistant Scientist, Biological Systems Engineering, University of Wisconsin-Madison

Mahmoud Sharara, Assistant Professor, North Carolina State University

Victor Zavala, Associate Professor, Chemical & Biological Engineering, University of Wisconsin-Madison

Apoorva Sampat, Chemical & Biological Engineering, University of Wisconsin-Madison

Yicheng Hu, Chemical & Biological Engineering, University of Wisconsin-Madison


This material is based on work that is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number 2017-67003-26055.



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