No other energy crop has been as closely associated with second generation biofuels as switchgrass. The subject of much fawning coverage in the popular press — though it has yet to be successfully converted into cellulosic ethanol — switchgrass will soon have the chance to provide its renewably energy bonafides in Oklahoma.

The Oklahoma Bioenergy Center (OBC), a partnership between Oklahoma University, Oklahoma State University and the Samuel Roberts Noble Foundation of Ardmore, will plant the world’s first production-scale switchgrass demonstration field near Guymon within the next 45 days. The Center also plans on planting production-scale fields for sorghum, another cellulosic energy crop.

Switchgrass is a perennial, or year-long, grass that can be grown on marginal lands and that is naturally drought-resistant; it is also a self-seeding crop, which means it doesn’t need to be re-seeded or planted after being harvested, and requires little to no fertilizer. Most importantly, it won’t produce the backlash that other crops, such as corn and soybeans, have done by displacing valuable agrarian land.

Initial tests conducted by the Department of Energy have demonstrated that its energy output is 20 times better than that of corn. It also found that a metric ton of switchgrass could produce the equivalent of 100 gallons of ethanol. Research done by scientists at Auburn University largely corroborated the DOE’s results, showing that an acre of switchgrass could yield up to 1,500 gallons of ethanol every year. The crop was highlighted for its alternative energy potential in President George W. Bush’s 2006 State of the Union address.

The demonstration fields will allow companies and scientists to experiment with new production and harvesting techniques and to compare switchgrass’ properties as a renewable fuel to those of feedstock biofuels. Officials from the OBC hope the findings from this experiment directly carry over into commercial-scale production of the energy crop.

Abengoa Bioenergy, a Spanish renewable fuels company, will use switchgrass from these fields in its Hugoton, Kansas, biorefinery, which is expected to be up and running in 2010. Companies like Mascoma, Range Fuels and Coskata have been capitalizing on the enthusiasm for cellulosic ethanol, raising record sums and forming partnerships with some industry heavyweights, like GM.

Another hardy energy crop that has been making waves is jatropha, a wild plant whose seeds are being used by several countries in Asia, including the Philippines and India, and Africa to produce biodiesel. It’s not hard to see why: Like switchgrass, the plant is drought-resistant, requires little fertilizer and can be grown practically anywhere — in deserts, on rock piles and even on trash. Its seeds, which contain up to 40% oil, are crushed and processed to produce the biodiesel; the residue can be processed into a form of biomass suitable to power electricity plants.

Seed yield estimates range from 1,500 to 2,000 kilograms per hectare — the equivalent of 540 to 680 liters of extractable oil per hectare. A recent Goldman Sachs analysis cited the crop as one of the most promising candidates for future biodiesel production. Last June BP announced it would invest $90 million in a joint venture with D1 Oils, a British firm, that specializes in jatropha.

Some questions still remain about jatropha’s viability as a long-term source of biodiesel, however: Because none of the jatropha species have yet been successfully domesticated, their oil output tends to be very unpredictable and — more often than not — much lower than expected. And even though it can be grown without water, it typically does much better with it — potentially negating some of its cost benefits. The worry among some analysts and academics is that farms could lose a bundle on jatropha plantations if their crop yields turn out flat.

Furthermore, jatropha takes about 3 years to grow and, in countries like India, where land is scarce, has been difficult to find — even on marginal lands, which are typically inaccessible by vehicle and, therefore, unable to support commercial-scale production facilities. And, while not necessarily relevant to its production capacity, jatropha’s seeds and leaves are poisonous to humans. Australia’s government banned it in 2006, citing its health risks and invasive nature.

In spite of this, jatropha growth is expected to remain strong as more farmers in developing countries convert otherwise unusable land to plantation fields — a trend that is likely to persist as global food prices, fueled in part by the biofuel boom, continue their rise. Oklahoma’s switchgrass demonstration should help businesses and local governments determine whether their investments in cellulosic energy will be worth it.