Sustainable by Design

How do we get biomass from the land while preserving—or even benefiting—its living communities? Whichever course we take, researchers at the CALS-led Great Lakes Bioenergy Research Center are determined to put all pros and cons on the table.

Meanwhile, the lack of markets for dedicated biofuel feedstocks, such as switchgrass, has created demand for cornstalks, slash from timber harvests, and other agricultural and forest “waste” as fuel sources for power plants, even though decades of research show these materials are critical to ecosystems—and that their removal could be damaging.

Even the promise Gratton and Meehan see in bioenergy crops could easily be wiped away. Much will depend on which crops are planted and where, as well as how much water, pesticides and fertilizers they need. Growing them might also release more of the greenhouse gas, carbon dioxide (CO2), than the plants pull in, negating what’s considered their premier advantage over fossil fuels.

The uncertainty has generated a flurry of new research in CALS.

“Biofuels are a force that we think is going to change things for the next 100 years,” says Kucharik. “So we want to make sure we get this right.”

Few people likely believed 10 years ago that biofuels could be gotten wrong, so naturally “green” did they seem. Then ethanol made from corn grain came along. Widely hailed at first as plentiful, non-polluting, and a cure-all for peak oil and climate change, it descended almost immediately into a storm of criticism for being, opponents contended, none of these things.

With every two of five rows of U.S.-grown corn destined for ethanol plants today, the cloud still hasn’t lifted, and now cellulosic biofuels are being similarly accused. The difference now is that federal agencies are paying more attention to the potential problems—and paying for research to help prevent them. The DOE, for example, funds the Great Lakes Bioenergy Research Center (GLBRC) based in CALS, whose team of engineers, microbiologists and other technology-focused types also includes scientists like Gratton, Meehan and Kucharik who study sustainability and ecosystem protection.

If this suggests that the health of farmlands is a newfound concern, however, biological systems engineering professor Doug Reinemann assures it is not. Disasters like the Dust Bowl, in which eroded topsoil blew up in vast, black blizzards for nearly a decade, taught the country long ago that soil and water needed protecting even as they were being used to produce food. The environmental regulations and programs that have since been enacted aren’t perfect, but they have taken us a long way from the days when livestock grazed in streambeds and sensitive lands were plowed up at will. Reinemann sees the emphasis now on ecosystem conservation as a natural outgrowth of these earlier efforts.

“It’s really a continuation of traditional soil conservation,” says Reinemann, who leads the GLBRC effort to model the impacts of biofuels crops on landscapes. “But I think we’re also looking at it in a broader sense, particularly with the issue of landscape diversity and the importance of insects, birds and soil microbes—that they’re essential in providing ecosystem services.”

One CALS scientist who was examining these questions long before biofuels became popular is agronomy professor Randy Jackson. A grasslands ecologist, Jackson has spent much of his career studying the environmental and agronomic value of seeding native prairie grasses, such as switchgrass and big bluestem, into pasturelands planted in more traditional forages. When the “biofuels juggernaut” came along, he says, the sustainability questions the GLBRC wanted to ask were right up his alley. He now co-leads its sustainability research group with Michigan State University professor Phil Robertson.

The group’s mantra is the “three Ps.” First, biofuels crops must be productive, Jackson says, because farmers need to make a living. Also favored are perennial plants, whose deep, lasting root systems cut erosion, build soil organic matter and scavenge nutrients, in contrast to corn and soybeans that leave ground bare in winter and must be replanted every spring.

Then there is polyculture, which simply means planting a mixture of species as one crop versus the monocultures we mostly cultivate today. Assortments of plants, the thinking goes, use nutrients more efficiently because individual species take them up at different times and they perform more functions, such as fixing nitrogen or resisting drought, than do single species.

GLBRC scientists are still debating a fourth “P”: placement on the landscape. “We aren’t so starry-eyed as to think that there won’t be monocultures planted in the future,” Jackson says. “So what we’re pushing for is that we maintain diversity between patches, so we have patches of switchgrass and corn and woody crops.”