Collaborative research shows manure to be a rich resource

Recently published research completed by Associate Professor of Natural and Applied Sciences, John Katers, and Watershed Outreach and Education Specialist, Annette Pelegrin, of the Cofrin Center for Biodiversity, could change the way the public views manure in years to come.

“In the future, manure will no longer be viewed as dilute fertilizer or waste product,” Pelegrin says. “It will be viewed as a valuable raw material for new products. Along with digestion, this innovative manure separation process can minimize environmental impacts and maximize the economic value of digested dairy manure.”

The journal, Applied Engineering in Agriculture featured their work, “Nutrient and Solids Separation of Digested Dairy Manure with Bench-Scale Polymer Treatment.” The project took 18 months of research, “from the beginning jar tests to the final on-farm trial,” according to Pelegrin.

This publication summarized the research completed by Pelegrin for her thesis project in the Environmental Science and Policy program, which was honored as the University’s Outstanding Thesis of the Year in 2010.

Pelegrin explained why the research and related technology could provide waste transformation opportunities for Wisconsin farmers.


Her findings show how water can be removed from manure, resulting in a low-nutrient liquid and a nutrient-rich sludge, which farmers will be able to transport more efficiently, thanks to the lighter weight due to the liquid being removed.

“This saves greatly on fuel costs, along with the added environmental benefit of reduced greenhouse gas emissions from transportation,” she said. “Additionally, farmers can pump the leftover low-nutrient liquid to irrigate nearby fields or they can use it to flush the barns. If pelletized, the concentrated sludge also has the potential to generate income as a commercial fertilizer.”

Katers noted that Dr. Aicardo Roa from SoilNet/UW-Madison was recently awarded a $7 million federal grant which will be used to build  a full-scale system using similar technologies.

Pelegrin said the most challenging part of her research was taking the “leap of faith” when taking her lab findings to the full-size farm trial. And it certainly was not all easy. She had some early lab trials that didn’t go exactly as anticipated, but she explained that through the support of her committee members and continued investigation, she was able to develop a deeper understanding.

“From this experience I learned that sometimes our greatest obstacles become our greatest opportunities for growth and discovery,” Pelegrin said.

An Agricultural Development and Diversification grant from the Wisconsin Department of Agriculture, Trade and Consumer Protection in conjunction with matching funds from ENCAP, LLC and its parent company FEECO International, Inc., both of Green Bay, Wis. funded the research. Green Valley Dairy in Krakow, Wis. and Soilnet, LLC of Madison, Wis. were also partners in the project.

Story by Michael Duenkel, Marketing and University Communication editorial intern
Photos by Annette Pelegrin

You may also like...