Looking for “Hotspots”

In their quest to make cellulosic biofuel a viable energy option, many researchers are looking to marginal lands—those unsuitable for growing food—as potential real estate for bioenergy crops.

But what do farmers think of that? Brad Barham, a CALS/UW-Extension professor of agricultural and applied economics and a researcher with the Great Lakes Bioenergy Research Center (GLBRC), took the logical next step and asked them.

Fewer than 30 percent were willing to grow nonedible cellulosic biofuel feedstocks—such as perennial grasses and short-rotation trees—on their marginal lands for a range of prices, Barham and his team found after analyzing responses from 300 farmers in southwestern Wisconsin.

“Previous work in the area of marginal lands for bioenergy has been based primarily on the landscape’s suitability, without much research on its economic viability,” says Barham, who sent out the survey in 2011. “What’s in play is how much farmers are willing to change their land-use behavior.”

Barham’s results are a testament to the complex reality of implementing commercial cellulosic biofuel systems. Despite the minority of positive responses, researchers found that there were some clusters—or “hotspots”—of farmers who showed favorable attitudes toward use of marginal land for bioenergy.

These hotspots could be a window of opportunity for bioenergy researchers since they indicate areas where feedstocks could be grown more continuously.

“People envision bioenergy crops being blanketed across the landscape,” says Barham, “but if it’s five percent of the crops being harvested from this farm here, and 10 percent from that farm there, it’s going to be too costly to collect and aggregate the biomass relative to the value of the energy you get from it.

“If we want concentrated bioenergy production, that means looking for hotspots where people have favorable attitudes toward crops that can improve the environmental effects associated with energy decisions,” Barham notes.

CALS agronomy professor Randy Jackson is also interested in the idea of bioenergy hotspots. Jackson, who co-leads the GLBRC’s area of research focusing on sustainability, says that just because lands are too wet, too rocky or too eroded to farm traditionally doesn’t mean they aren’t valuable.

“The first thing we can say about marginal lands is that ‘marginal’ is a relative term,” says Jackson. Such lands have a social as well as a biophysical definition. “This land is where the owners like to hunt, for example.”

The goal of GLBRC researchers like Barham and Jackson is to integrate the environmental impacts of different cropping systems with economic forces and social drivers.

The environmental benefits of cellulosic biofuel feedstocks such as perennial grasses are significant. In addition to providing a versatile starting material for ethanol and other advanced biofuels, grasses do not compete with food crops and require little or no fertilizer or pesticides. Unlike annual crops like corn, which must be replanted each year, perennials can remain in the soil for more than a decade, conferring important ecosystem services like erosion protection and wildlife habitat.

The ecosystem services, bioenergy potential and social values that influence how we utilize and define marginal land make it difficult to predict the outcomes of planting one type of crop versus another. To tackle that problem, Jackson is working with other UW–Madison experts who are developing computer-based simulation tools in projects funded by the GLBRC and a Sun Grant from the U.S. Department of Energy.

Jackson hopes that these modeling tools will help researchers pinpoint where farmer willingness hotspots overlap with regions that could benefit disproportionately from the ecosystem services that perennial bioenergy feedstocks have to offer.

“These models will include data layers for geography, crop yield, land use, carbon sequestration and farmer willingness to participate,” says Jackson. “There could be as many as 40 data layers feeding into these models so that you can see what would happen to each variable if, say, you were to plant the entire landscape with switchgrass.”

Wisconsin’s “Brown Gold” Rush

Earth’s petroleum stores are dwindling, but a Wisconsin project aims to produce energy from a resource that’s in little danger of running low: cow manure, or “brown gold.”

The University of Wisconsin–Madison and several state companies, funded by a $7 million grant from the USDA Biomass Research and Development Initiative (BRDI), have partnered to pilot the conversion of dairy farm manure into useful product streams—a project that is expected to have significant environmental and economic benefits.

The Accelerated Renewable Energy (ARE) project is in progress at the 5,000-cow Maple Leaf Dairy in Manitowoc County, where animal waste is separated into different streams, or fractions, of processed manure.

After small plant fibers in the manure are separated and anaerobically digested to biogas, liquids from the digestion process are used to fertilize crops, while solids can be converted into useful chemicals and bio-plastics. Larger plant fibers make great animal bedding and mulch, not to mention a starting material for ethanol fermentation.

Meanwhile, at the new Wisconsin Energy Institute at UW–Madison, project co-investigator Troy Runge, a CALS professor of biological systems engineering, is analyzing the ARE project’s separation techniques to improve their efficiency. “We are performing many of the same separations that occur on the farm, but in the controlled environment of
the lab to both measure and optimize the system,” says Runge.

Tom Cox, a project collaborator and a CALS professor of agricultural economics, sees great potential for the initiative. “This is a triple-win situation; we would like to make money by doing the right thing by the environment and society,” he says.

Aicardo Roa-Espinosa MS’85 PhD’89, president of partner SoilNet LLC and an adjunct faculty member in biological systems engineering, developed the manure separation technology behind the project. Roa-Espinosa and Runge will monitor the quality, quantity and composition of biogas produced and analyze processed manure streams to identify chemical constituents. Student researchers will conduct life cycle assessments to evaluate the project’s environmental impact.

The goal for the four-year grant, researchers say, is to improve these manure separation technologies until their sustainability benefits can be realized on a broader commercial scale.

Runge notes that the public-private, multidisciplinary project exemplifies what the university hopes to do with the Wisconsin Energy Institute. “It’s also an example of a project that’s important to Wisconsin,” he says.

Indeed, the project may help farmers manage manure with benefits for both the environment and human health. A 5,000-cow dairy farm like Maple Leaf produces approximately 25 tons of manure per day, which require millions of gallons of water to manage. Although some manure may be used as fertilizer, nutrient imbalances and runoff can create environmental problems. However, manure processed using SoilNet’s technology yields concentrated, homogenized fertilizer that can be applied with greater control over nutrient content.

In addition to its environmental benefits, the cellulosic—or non-food—plant biomass derived from dairy manure avoids the conflict of “food versus fuel.”

That’s a promising basis for exciting innovations at dairy farms. For ARE project leaders, farms are not only the heart of agriculture. They also have the potential to serve as foundations for cellulosic biorefineries that could prove key in supporting a local green economy and a sustainable energy system throughout the region.

Biofuel for Teens

As students in Craig Kohn’s class at Waterford Union High School can tell you, you don’t need a grant or Ph.D. to do scientific research. A question and some curiosity are all that’s needed—along with a sturdy pair of gloves.

Kohn BS’08, who earned degrees in biology and agricultural education at CALS, teaches a class called Biotechnology and Biofuels in which students hunt for bacteria that naturally secrete enzymes called cellulases. Cellulases are named for their ability to break down cellulose, the sugar polymer in plant cell walls that gives stems and leaves their structure.

“Cellulases are important for bioenergy because they are necessary to turn cellulose into a fermentable product that can be made into ethanol and other biofuels,” says Kohn.

To find those cellulase-producing bacteria, Kohn sends students out to collect samples from the compost heaps and animal pens behind their school in a quest known as “bioprospecting.”

Back in the classroom, students drop the samples into test tubes filled with media solution and a strip of filter paper. If cellulases are present, the cellulose-based paper will disintegrate as the enzymes do their work.

That process of discovery excites students. “You see this light in their eyes when they realize that they are participating in science directly, and that their work could lead to actual breakthroughs and results,” Kohn says.

Kohn developed the activity as a participant in “Research Experience for Teachers,” a program at the UW’s Great Lakes Bioenergy Research Center (GLBRC). For his project he shadowed Cameron Currie, a CALS professor of bacteriology and a GLBRC researcher who uses genomic and ecological approaches to study biomass-degrading microbes.

“Teachers are not only learning about current science—they are embedded in the lab,” says John Greenler, GLBRC’s director of education and outreach. “When teachers have that primary experience, they are in a better position to engage their students because they ‘get it.’”

Connor Williams, a high school senior who helped develop the bioprospecting lab with Kohn through his participation in the National FFA Organization (formerly Future Farmers of America), says his favorite element is the hands-on, independent work.

“I learned that answers to biofuel challenges literally can be found right in our backyards,” Williams says. “You just need to know where to look.”