At Michigan State University, Kurt Thelen is one of many GLBRC researchers focused on tackling this issue head on.

Despite the enormity of the challenge, Thelen isn’t fazed.

“It is a very exciting time to be involved in agriculture,” says Thelen, an MSU professor of plant, soil and microbial sciences. “I’m optimistic for the future.” 

As Center researchers consider which crops to grow, where they’ll be grown, and the new systems, equipment and supply chains that are needed to tie them all together, sustainability is key.

Biochemists and engineers explore multiple sugar-to-fuel conversion strategies, while plant breeders and agronomists are working to determine what types of bioenergy crops are most suitable for different landscapes.

“One thing that is clear is that biomass is local,” says Thelen. “There are niches for a lot of different types of plants.”

Using historical data from sites like the Kellogg Biological Station’s LTER program and recently established bioenergy test plots in Michigan and Wisconsin, GLBRC researchers have learned more about top crop contenders and are beginning to explore the land management challenges that are on the horizon for farmers.

One hallmark characteristic of the so-called 'gold standard' biofuel crops like switchgrass and corn stover is their productivity. These crops stand out not just because of their reliable yields, but also because they can be grown in close proximity or close succession to other perennial crops that have the ability to sequester more carbon and improve habitats for local wildlife. The abundance of available U.S. corn stover and the adaptability of switchgrass across a wide range of soil and environmental conditions make these crops excellent cellulosic feedstocks, according to the DOE.

Landowners who start to use corn stover as a near-term feedstock will need to carefully balance soil health with biomass yield.

“As a general rule, you can probably remove about one-third of stover on most acreage in the Great Lakes Region without depleting soil organic matter,” says Thelen. “If we start taking more than that, we run that risk, which isn’t sustainable.”

GLBRC researchers are also investigating the feasibility of using fast-growing poplar and Miscanthus. Current challenges for Miscanthus include establishing the crop successfully, and poplar is more difficult to deconstruct than switchgrass and corn stover. Because of these issues, poplar and Miscanthus are classified as 'silver standard' crops.

Labeling plant species as either gold or silver standards helps researchers characterize their advantages and disadvantages as bioenergy sources, but the simplicity of dropping feedstocks into tidy categories does not reflect the complex reality of growing them in the ground. Once regional feedstock species are determined, the next step is to find a formula for growing them successfully in a way that benefits not only landowners and energy producers, but also the land itself.

Thelen notes that land management strategies under discussion often involve asking the land to multitask — either by integrating perennials into the usual crop rotation, or by planting winter annuals in between primary crops like corn. This approach, called double cropping, could allow landowners to reap additional revenue from the sale of cellulosic biomass for fuel while they continueto grow food crops.

In other cases, maintaining a balance between profitability and sustainability may be all in the timing. Thelen explains that when perennial feedstocks like switchgrass are harvested in their prime, they contain abundant nutrients that can be used to nourish livestock. But bioenergy harvest occurs at the end of the growing season, after plants have naturally moved nutrients to their roots — meaning these valuable nutrients remain in the farmer’s soil for another fertile growing season.

“In terms of bioenergy, it is a benefit for the farmer to keep those nutrients in the soil, which is why perennial crops are so useful from a sustainability standpoint,” Thelen explains.

In his work with farmers, Thelen says that he is encouraged by the excitement they show for these types of new opportunities—and possibly also increased opportunities for profit.

Modeling and mapping data have shown that while marginal land may be an option for growing more biofuel feedstocks, many of these acres are in small tracts of 25 acres or so.

If biomass on that land is to be used for cellulosic biofuel it will need to be compiled or aggregated, which Thelen says creates an opportunity for custom equipment operators to do planting or harvesting of new energy crops.

“Farmers with less acreage don’t typically fork over the money for a quarter-million dollar self-propelled combine,” Thelen says. “They are already reaching out to custom operators who are equipped to plant or harvest.”

Thelen imagines that biofuels harvest, aggregation and processing scenarios could easily follow the developmental pattern of other small farm agriculture and livestock operations.

“The whole idea of local depot centers is very well grounded in reality,” he says. “That’s what we have now for agricultural commodities, and that’s what we have for local grain elevators.”

Thelen hopes that these food industry systems can serve as models for local biomass processing centers, which could take responsibility for pre-processing and compacting biomass for shipping and conversion to fuel.

“It is very intuitive that bioenergy crops would evolve the same way as the food system has. The food system evolved that way for a reason: because it works…and so we could use the same advantageous strategies to handle bioenergy crops,” says Thelen.

Ultimately, the inspiration behind synergistic and ‘multi-purpose’ biofuel strategies like double cropping, marginal lands, and integration into existing agricultural systems speaks to the need for sustainable energy technologies that can support a growing population over the long-term.

Predictions estimate that by 2020, farmers must increase crop yields by 40 percent to support the world’s food, fiber and fuel consumption. In order to meet this need, an additional 10 percent of land area will be required.

“You can design a system that is economical and protective of the environment from a scientific standpoint, but the challenge is making it fit in with the needs and goals of landowners,” Thelen says.

However, if there is one thing the GLBRC knows about, it is taking a challenge and turning it into an opportunity. Multi-purpose landscapes present the tantalizing possibility of producing much-needed renewable fuel in a manner that supports both farmers and their lands.

“By some estimates, Michigan alone has four million acres of abandoned farmland, located primarily in the northern lower peninsula,” Thelen says. “These soils are marginal for food crop production, but well suited for a perennial grass or short rotation woody biomass system. By virtue of our geography, the Great Lakes Region has potential for being a significant player in the emerging bioeconomy.”