By Sandy Miller Hays
As printed in the The Southwest News-Herald, May 21, 2007.

Everybody's talking about "green products" these days: products that are biodegradable, come from renewable plant resources rather than petroleum, and are generally good for the environment. The list ranges from carpet backing and cleaning compounds to wood glues, and every conceivable product in between.

But when it comes to alternative fuel sources for our cars and other machinery, the scientists of the Agricultural Research Service (ARS) are really "thinking green" – as in "green, green grass."

We've all heard about the wonderful native plant called switchgrass. It's a tough perennial, capable of thriving under a whole host of environmental conditions, and it grows like... well, a weed, producing up to 16 tons of dry matter per acre in the Southeast. And each ton of that dry matter could yield as much as 96 gallons of ethanol. It also provides excellent habitat for ducks, pheasants and other wild creatures.

But the ARS scientists say the story doesn't stop at switchgrass – and in some cases, it starts a whole lot closer to home. In fact, they say our old backyard friend bermudagrass could be a contender. Bermudagrass' pluses: It's already grown on millions of acres as forage in the United States, and in addition to being highly digestible for livestock, it has good potential for conversion to ethanol.

Here's one you're probably less familiar with: bahiagrass. Like bermudagrass, it's a perennial plant, which means that once you've gotten it started, you don't have to keep replanting year after year. While it offers less yield and lower quality than bermudagrass, it has definite advantages: It grows well in marginal land, and getting it started is a snap.

A third possibility is napiergrass. It's different from bahiagrass and bermudagrass in that it could be totally dedicated to energy use. The ARS scientists report that in a six-year study in Georgia at three locations, napiergrass out-yielded bermudagrass and switchgrass by 5 tons of dry matter per acre per year. And in preliminary studies, it worked just as well as switchgrass in ease of conversion to ethanol.

That's just the start of the list, the scientists say. Other candidates – all of them easy to grow and maintain – are smooth bromegrass, orchardgrass and reed canarygrass. The researchers think these grasses have the potential to feed both our nation's cattle herd and our enormous energy appetite.

Some of those grasses may not be familiar to you, but here's a plant that I can almost guarantee you've heard of: alfalfa.

Unlike corn and other grasses, alfalfa is a legume: it's able to "fix" its own nitrogen. That means the plant can take nitrogen from the air and change it into a form it can use to fuel its own growth; in other words, it makes its own fertilizer!

The ARS scientists would like to make alfalfa even better, though, by boosting the amount of dry matter it can produce. For example, they'd like to improve alfalfa's ability to hold onto its leaves. Because alfalfa plants are grown very close together, many of the lower leaves simply drop off from lack of sunlight. The scientists hope to find a way to stop the loss of that valuable plant matter.

In fact, they're collaborating with the Noble Foundation in Ardmore, Okla., to try to build the ideal alfalfa plant. One improvement would reducing its levels of lignin, the natural cementing agent that holds cell walls together. With lignin out of the way, it's easier to get to the cell walls' sugars that can be converted into fuel.

The ARS-Noble team is tackling different parts of the problem. Noble produces plants with reduced lignin, and then the ARS scientists use various analytic techniques to see what the modified cell walls look like and how easily they can be processed by a cow's digestive system or for biomass conversion into energy.

But bioenergy is only part of the picture. For example, ARS researchers have found that alfalfa is a good source of quality protein and health-promoting nutraceuticals. Also, its bits of fiber can be used as a water-filtering agent, and it's an ideal ingredient for making an all-natural glue.

This grass is definitely looking greener every day!

This article appeared in The Oklahoman, The Southwest News-Herald, on May 21, 2007.