Energy wonder crop Arundo raises invasive fears

jmurawski@newsobserver.comSeptember 24, 2012 

  • About the plant

    Botanical name: Arundo donax

    Common names: Arundo, Giant Reed, Wild Cane

    Native to northern Africa and the Middle East, Arundo can reach a height of 30 feet, resembles corn and bamboo, and is used to make reeds for woodwind instruments. It has naturalized in Europe, Asia, Australia, Africa, South America, as well as in this country. It’s listed as invasive or a noxious weed in Georgia, South Carolina, Tennessee and Virginia.

    Originally planted in irrigation channels and drainage ditches in California in the 1800s, Arundo has cost the Golden State more than $70 million in eradication efforts in the past two decades.

    In the United States it does not produce viable seeds but spreads by fleshy roots called rhizomes, and also propagates when its tall stalks break off, or fall over, and root on contact with wet soil. Arundo is not known to have natural predators and pests in this country, and the primary barrier to its spread is cold weather.

    Opinions are divided about the plant’s risks. The U.S. Dept. of Agriculture said in June it is considered by some to be a ‘transformer’ species because it dramatically alters habitats and ecological processes. The European Commission has called the giant reed one of the most cost-effective crops that is environmentally friendly.

    Staff writer John Murawski

It’s billed as a champion energy crop that yields three times as much ethanol per acre as corn, a fast-growing field grass that’s ideal for making clean auto fuel without displacing scarce crop land. The N.C. Biofuels Center has been pushing for more than a year to grow the Arundo plant on a mass scale, touting it as a new cash crop and the prime energy source for a proposed $170 million biofuel refinery in eastern North Carolina.

But the bamboo-like grass has a dark side. Some scientists have called Arundo “the plant from hell” and rank it among the world’s 100 worst invasive plants.

“Arundo has got a lot of us scared,” said David Crouse, an N.C. State University soil scientist. “We have that concern that it could be kudzu-like.”

Even some board members of the Biofuels Center are trying to stop the organization from spreading Arundo on North Carolina’s soil. The Environmental Defense Fund, whose Southeast director, Jane Preyer, sits on the Biofuels Center’s board of directors, is among a half-dozen state and national organizations that has petitioned North Carolina officials to declare Arundo a noxious weed and get it banned or restricted in the state.

The lore about the Arundo is that it can grow up to 10 inches a day, resprout from roots buried 9 feet deep, and burrow under roadways to infest neighboring fields. It’s nearly impossible to get rid of once established in some states. California has spent more than $70 million on eradication programs over the past two decades.

Still, Arundo has a lot of powerful backers who say that the wild cane can be managed in North Carolina so that it doesn’t take over native habitats. The fast-growing plant’s chief asset is the massive volume of vegetation – and consequently ethanol fuel – it can produce in poor soil with minimal fuss and at minimal cost.

“It’s a miracle plant in that you can grow it on less land and you get higher mass,” said W. Steven Burke, CEO of the N.C. Biofuels Center in Oxford. “It’s the most promising in the terms of volume, of mass to be gained: up to 18 tons per acre. Wow.”

The U.S. Department of Agriculture last month promised $99 million in loan guarantees for the Chemtex ethanol refinery in Sampson County, an attempt to create a new domestic energy industry that could offset imported oil. Chemtex has developed a similar plant in Italy that is expected to use Arundo for 90 percent of its plant source. The North Carolina facility would rotate energy crops and use Arundo for as much as half the vegetation that would be chemically converted to ethanol fuel for cars and trucks.

The fate of the local Chemtex facility, which would employ 65 people, remains iffy without Arundo in the fuel mix. Chemtex would also rely on less energy-intensive crops such as sorghum and switchgrass, that would supplement Arundo.

“It’s certainly the first choice,” said Matt Harrod, director of Agri Supply Chain Development at Chemtex. Harrod said the economics of the facility assume a supply of at least 100,000 tons of Arundo a year, to be grown on farms in Johnston, Bladen, Duplin and Sampson counties.

The Chemtex project depends on a favorable ruling from the N.C. Department of Agriculture that Arundo is not a noxious weed. A recommendation is expected by early next year.

But it also depends on a decision from the Environmental Protection Agency classifying Arundo as an energy crop for making high-grade ethanol. The premium biofuel is expected to cost as much as $1 more per gallon than conventional ethanol, Harrod said. This class of premium-grade ethanol is currently not commercially available.

To calm fears, the N.C. Biofuels Center has issued safe growth management practices and has enlisted scientists at Ohio State University and Virginia Tech to vouch for the safety of Arundo. They say the reedy grass is easy to control as long s it’s kept away from drainage ditches or waterways, noting that Arundo is a common landscape ornamental plant sold by nurseries.

“It should not be assumed that Arundo will become invasive in all circumstances and locations,” according to the analysis by Jacob Barney, a professor of weed science and plant physiology at Virginia Tech.

Two leading state agricultural officials have lobbied for Arundo’s cultivation in North Carolina. Steven Troxler, the state agriculture commissioner, along with Johnny Wynne, the recently retired agriculture dean of N.C. State University, petitioned the N.C. Department of Environment and Natural Resources last year to fast-track Arundo for approval to be grown on fields where nutrient-rich swine waste is sprayed. Like Preyer of the Environmental Defense Fund, Troxler and Wynne were members of the board of directors at the Biofuels Center, but Wynne stepped down when he retired in November.

Chemtex would like farmers to grow Arundo on swine spray fields, which are strictly regulated by the federal Clean Water Act to prevent drainage of nitrogen into nearby waterways. Farmers get rid of their excess nitrogen, a component of swine waste, by planting vegetation that consumes high amounts of the chemical element as food, primarily Coastal Bermudagrass, which sucks up 250 pounds of nitrogen per acre a year.

Nitrogen left on spray fields that is not absorbed by plants will flow into nearby streams, accumulate in waterways and cause algae infestation, which then clogs the water and results in fish kills.

Troxler and Wynne had asked for an exemption to allow Arundo on some spray fields instead of Coastal Bermudagrass. Arundo is believed to take up only 60 pounds of nitrogen a year – about a fourth of the rate of the Bermudagrass – and a double harvest would absorb 120 pounds of nitrogen. That estimate was affirmed by a state panel that in June rejected Troxler’s and Wynne’s request for a waiver.

N.C. State scientists say the state waiver on nitrogen runoff, if granted, would have met resistance at the federal level. Allowing excess nitrogen runoff on local farms could expose North Carolina’s hog farmers to violations of the federal Clean Water Act, which carries fines of $10,000 a day per violation, Crouse, the N.C. State soil scientist, said.

Crouse expressed concern about allowing nitrogen runoff into rivers, in a May email to the Biofuels Center, saying “this is a very dangerous game being played in the name of biofuels.”

The nitrogen issue has been temporarily resolved by the June ruling, but it is not over. Arundo is under review by a state panel to see if the preliminary consumption estimates for nitrogen are accurate or if they should be revised. The final nitrogen usage rates for Arundo will be completed in 2014, the date the Chemtex plant is scheduled to begin operating.

Currently it is legal to grow Arundo in North Carolina and the reeds are used as a landscape plant throughout the state. Scientists say that the chances of infestation go down with several factors: growing single plants rather than several thousand acres, as well as planting Arundo far away from rivers, lakes and wetlands.

“It’s an amazingly dangerous plant,” said ecologist Sam Pearsall, the Environmental Defense Fund’s southeast manager for water and wildlife programs. “All it takes to propagate the stuff is for the stalk to fall down on the ground, and the nodes in the stalk put down roots and grow.”

“The fact is that a hurricane or a flood is capable of taking Arundo vegetative matter all over the place.”

Murawski: 919-829-8932

News & Observer is pleased to provide this opportunity to share information, experiences and observations about what's in the news. Some of the comments may be reprinted elsewhere in the site or in the newspaper. We encourage lively, open debate on the issues of the day, and ask that you refrain from profanity, hate speech, personal comments and remarks that are off point. Thank you for taking the time to offer your thoughts.

Commenting FAQs | Terms of Service