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WSU Researchers Receive USDA Grant to “Beef-Up” Digester Co-Products

PULLMAN, Wash. — Manure. It’s ugly, it smells, and getting rid of it can be a messy problem for agricultural producers throughout the country. Thanks to a grant from the U.S. Department of Agriculture, however, researchers at Washington State University will be working to find a new way for producers to make money from it.

The $683,000 grant was made possible through the USDA’s Natural Resources Conservation Service Conservation Innovation Grant program, which this year provided 41 grant awards nationwide. The new program, authorized in the 2002 Farm Bill, provided more than $41 million in innovation grants this year.

James Moseley, deputy agriculture secretary, came to WSU Thursday (Sept. 16) to present the grant.

A team of researchers at WSU’s College of Agricultural, Human, and Natural Resource Sciences will use the grant to further research into high- quality fiber and fertilizer as co-products from anaerobic digestion. The team will explore methods for extracting two high-value products from liquid manure: a high-quality fiber that can substitute for peat moss as a type of “super soil conditioner” and a slow-release fertilizer.

The WSU research team includes Shulin Chen, professor of biological systems engineering; Craig MacConnell, Whatcom County extension educator; Joe Harrison, extension dairy specialist; Richard Shumway, professor of economics; and Chris Feise, director of the Center for Sustaining Agriculture and Natural Resources.

Through a process known as anaerobic digestion, animal manure can be transformed from its original state into three basic and potentially useful products. One of the co-products from the process is methane, which can be used in electrical power generation. A second co-product is a fibrous, organic material that is a perfect soil conditioner for nursery plantings and home gardening. The third co-product is a slow-release, crystallized solid called struvite that is rich in nutrients, including nitrogen and phosphorus.

The key for researchers is to find ways to optimize the production of the nutrient-rich struvite and the fibrous, organic material and to effectively combine the two for commercial sale. “If we can find a commercially viable way of doing this,” Chen said, “agricultural producers could have an additional stream of revenue, and that would encourage the use of anaerobic digesters and improve the economic viability of agricultural operations.”

According to Chen, in the Pacific Northwest, with its relatively inexpensive electricity, the revenue from digester power generation alone is not sufficient to offset the cost of the installation, maintenance and operation of small to mid-size digesters. Therefore, the fiber needs to be acceptable in higher value markets, such as a replacement for peat moss in the ornamental industry with this local and renewable product, in order for the digesters to be economically viable, MacConnell said.

“We see this potential market niche as an opportunity for agricultural producers throughout the country,” Chen said. “Our challenge is to find a practical way to improve the quality of the fibrous product and to extract and utilize the nutrients in an economical and environmentally sustainable way. This grant will help us do just that.”

“By providing these grants, USDA is empowering the research community and the private sector to find innovative approaches to natural resource conservation,” NRCS State Conservationist Gus Hughbanks said.”WSU’s research has wide-ranging, practical implications for agriculture and the environment. We’re delighted to help WSU in developing this technology.”

The NRCS Conservation Innovation Grant complements the current digester and by-product work that are a part of the larger Climate Friendly Farming initiative led by WSU’s Center for Sustaining Agriculture and Natural Resources. The CFF initiative is working to move agriculture from a source of greenhouse gas emissions to a sink, while maintaining profitability and other environmental gains. Major funding is provided by the Paul G. Allen Charitable Foundation.

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Media Contacts

Ron Nichols, USDA Natural Resources Conservation Service, 509-323-2912
Chad Kruger, WSU Center for Sustaining Agriculture & Natural Resources, 509-663-8181 x235