U of I studying feasibility of products made from dairy waste

By John O’Connell

University of Idaho

University of Idaho researchers are pioneering technologies that have potential to turn a liability for dairymen – animal waste – into revenue-generating products.  

What would setting up commercial operations to transform dairy manure and lagoon water into usable products entail logistically? Would consumers accept products made from cow excrement? Would it be cost-effective to produce them? How should supply chains be established? 

A team of U of I agricultural economists is seeking to answer those key questions by building on technological discoveries made by other U of I researchers as part of a five-year, $10 million USDA Sustainable Agricultural Systems grant.

More than 20 U of I faculty members and several graduate students are participating in different aspects of the research.  

“We’re trying to use resources already on a dairy in more ways to increase revenue and reduce costs for dairy farmers and improve the environment in the region,” said U of I agricultural economist Patrick Hatzenbuehler.  

Work under the grant started in September 2019, initially focused on manure application and its effects on soils and nutrient uptake by crops.

Future research will expand into the economics of converting manure into renewable bioplastic, as well as separating it into valuable, concentrated crop nutrient components that can be substituted for commercial fertilizer.

A third project involves studying the feasibility of commercializing technology using iron and ultraviolet light to sterilize dairy lagoon water and capture the nitrogen, potassium, phosphorus and biochar it contains for application on crops.  

Demand for manure is currently on the rise due to record high fertilizer prices, and manure also can improve soil organic matter and microbial activity. Thus, increasing revenue or reducing costs from more efficiently obtaining nutrients from manure is a topic of great interest for many dairy industry stakeholders.

One economics study will evaluate the willingness of consumers to pay for bioplastics derived from dairy waste.  

“We could come up with dairy manure-based bioplastic at competitive market values with the upside in it being from renewable sources,” explained U of I agricultural economist Hernan Tejeda.  

Pilot studies have been conducted elsewhere on the use of bioplastics as a substitute for mulch in agricultural production, which could be a primary use for the product.  

Mark McGuire, associate dean of research with U of I’s College of Agricultural and Life Sciences and director of the Idaho Agricultural Experiment Station, is the grant’s principal investigator.  

“The grant is really designed to try to develop business and marketing plans for these technologies, like the bioplastics, to demonstrate the economic social viability, meaning it does help the environment or can play a role in the dairy industry being sustainable,” McGuire said. 

McGuire anticipates that a U of I-led research dairy that’s now under construction in Rupert, the focal component of the Idaho Center for Agriculture, Food and the Environment (CAFE), which will begin milking operations in 2024, will facilitate research during the final three years of the grant.  

“I’m hoping CAFE really demonstrates to producers that there’s a suite of new technologies that allow them to capture nutrients out of manure, and by doing so opening new markets and ways to generate revenue for their dairy,” McGuire said.

Rick Naerebout, executive director of the Idaho Dairymen’s Association, also sees a need to develop emerging technologies to convert manure for other uses. His organization has invested about $250,000 dating back about eight years in U of I’s bioplastics research.  

“We are bringing all of these nutrients into the state. We definitely need to spread them further away from dairy facilities,” Naerebout said. “That’s why we’re looking at novel ideas to generate revenue to make that more of a sustainable proposition for dairymen.”