Miscanthus x giganteus: way of the future?

It looks as though John Caveny has imported a jungle to his 35-acre farm in Monticello, IL.

John Caveny stands beneath this year’s crop of Miscanthus grass on his farm in Monticello. A sustainable farmer, Caveny hopes that one day the sterile, noninvasive hybrid grass can be widely grown for biofuel.

But what appears to be the beginning of some vast tropical hinterland is in fact Caveny’s crop of Miscanthus x giganteus, a tall perennial from Southeast Asia.  Caveny, who describes himself as a “practical conservationist,” grows the grass for its impressive biomass, which can be converted to fuel, and its ecological benefits.  He has recently completed 10 years of on-farm trials in conjunction with the University of Illinois in Champaign Urbana.

“If users are going to switch from fossil fuels they have to have reasonably good assurance that there will be adequate supplies of fuel,” he said, adding that this was one of the trial’s main questions.  And the answer?  “Yes, we can grow enough material.”

The grass, which reaches its full height of about 12 feet in late July, is a naturally occurring sterile cross between the Miscanthus sinensis and Miscanthus sacchariflorus.  Because it is sterile, it must rely on underground rhizomes to propagate.  These rhizomes are easily manipulated for transplant and grow so slowly they are incapable of becoming invasive, Caveny said.

The grass isn’t a food crop either, said Peter Schubert, senior director for space, energy and education research at Packer Engineering.  This is a good thing: whereas corn and soy, other biofuel candidates, are also used for consumption, Miscanthus cannot be eaten.

“The tradeoff between food and fuel is not sustainable,” Schubert said.  In other words, corn-for-fuel and corn-for-food would have to fight for the same fields.  The grass, however, grows happily on acres that are otherwise too polluted or arid to be used for food.

Miscanthus can be grown on marginal almost non-arable land, and convert those acres to productive energy source,” Schubert said.

The grasses require very little input.  They get their water from rain and the water table and, save a one-time fertilization during their first year, all their nutrients from the soil.  After its third year, the grass has reached a ceiling yield, and will continue to produce roughly the same amount of biomass every year for the next three decades.

Other benefits include soil retention, carbon sequestration and wildlife habitats, according to the trail.  But despite its many environmental boons, Miscanthus is not eligible for grown on land trusts, parcels set aside for conservation, Caveny said.

This makes it harder to find the space that would make growing the grass efficient.

Besides, not everyone is convinced this is such a good idea.

“I don’t think it’s the solution,” said Kim Grey, professor of civil and environmental engineering at Northwestern University.  Grey doubts that biofuels could ever fully replace the gasoline, kerosene and diesel used for automobiles, trains and airplanes.

“If you look ten years down the road, is that really where our fleet is going?  Maybe this provides us with a transition, but it isn’t long-term.”

But maybe transitional technology isn’t such a bad thing, said Schubert.

“There are very few technologies that could solve the entire industry problem,” he said.  “Turning energy crops into fuel will always be an important part of the future energy portfolio of mankind.”

Caveny agrees that until we move away from liquid fuels altogether, alternative sources will be important, especially cheap ones that produce a high yield and environmental benefits.

“Our culture works based on high-yielding crops no matter what you grow,” Caveny said.  But a history of subsidizing certain crops and not others has created a false profitability picture.  Along with the rules governing use of land conservancies, that’s one of the things he will work to change in the future.

“Take the subsidies out and let every crop grow on its merits, and then you’re going to see the energy crops become extremely profitable,” he said.

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