Grass of the past may help to shore up future for Iowa lake

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In the rolling hills of south central Iowa, where tall prairie grasses once sustained passing herds of bison, a growing number of people believe the region’s ecological and economic future may tied to the grass of the past.

Over the years, the land was converted to crops that took a toll on some of region’s poor, highly erodible, soils. This has also taken a toll on one of the area’s key resources: Rathbun Lake, which has become increasingly silted and fouled with runoff.

To help protect the 11,000-acre lake, the region has undertaken the nation’s most aggressive effort to find ways to shore up the soil with switchgrass — and make it pay for farmers.

The U.S. Department of Energy is supporting a pilot project that will use switchgrass grown in the watershed to eventually provide 5 percent of the fuel at Alliant Power’s 750 megawatt coal-fired Ottumwa Generating Station.

Ultimately, that would require 50,000 acres dedicated to growing switchgrass, with up to 500 farmers participating in the program.

ýo help out, the U.S. Department of Agriculture is allowing 4,000 acres of land enrolled in the Conservation Reserve Program to be managed and harvested in a four-county area as part of research aimed at finding the best production methods for growing switchgrass for use in the plant. The program eventually would expand to more counties in the lake’s watershed.

The use of CRP land allows farmers to reduce risks by providing them some income during the switchgrass establishment period, which can take two years or more. It also creates the stash of fuel needed for the power company to go ahead with modifications and testing.

Interest among farmers is high, even among those who don’t have land enrolled in CRP.

“There is a lot of interest outside of our four-county area, but there are a lot of factors that have to play out for that to be economically feasible,” said Velvet Glen, who oversees the project for the USDA’s Chariton Valley Resource Conservation and DevelopŒent Area. Without DOE support, which is paying farmers about $60 a ton for switchgrass, she said the project would be “dead in the water.”

In 2003, the plant is to start test burning 12.5 tons of switchgrass per hour. If successful, it will be ratcheted up to 25 tons — or 5 percent of the plant’s total fuel — in 2004.

Although tests have shown that the plant can burn switchgrass, it has resulted in an unanticipated side effect: The fly ash from the plant no longer has the consistency needed to be sold as a cement ingredient, a major source of income for the plant.

So a “gassifier” is being tested that would turn the switchgrass into a gas which would burn with the coal.

With such a strong interest in switchgrass, though, not all bets are hinged entirely on the plant. The project is coordinating a variety of research aimed at quantifying other benefits that may pay off for farmers.

The Iowa Farm Bureau, for example, is supporting research on the extent to which switchgrass can sequester carbon in the ground while it is being harvested and burned. If it can do both jobs at once, it may eventually clear the way for farmers to get cash payments for carbon sequestration as well as switchgrass sales — in effect, getting two payments for one crop.

In addition, a nonprofit cooperative of switchgrass farmers, Prairie Lands Bio-Products, was created in 1997 to support switchgrass research and marketing. It has identified a range of potential switchgrass markets: manufacturing into pellets and logs for fuel; mulch for landscaping; fiberboard and paper; and even use as fill in the manufacture of plastics.

The optimism in the area has led some farmers to take chances that may have been unimaginable a few years ago. One Prairie Lands member, who had 180 acres of CRP land planted in switchgrass, had to decide what to do with the land when the CRP contract expired. Rather than convert it to row crops, he decided to keep the land in switchgrass and find a market.

He gets 150 to 200 pounds of seed per acre of plants, which he sells for $4-$5 per pound. He sells the remaining straw to highway construction contractors, at $45 a ton, for use as mulch at construction projects.

If the economics work on a large scale, switchgrass could be the salvation for Rathbun Lake, which is a water supply for 50,000 people in 18 counties. It drains a watershed of 354,000 acres. More than one-third of that — 133,000 acres — is highly erodible land dedicated to row crops such as corn.

According to one analysis, if 50,000 acres of highly erodible land were converted to switchgrass production, it would reduce the soil erosion rate on those acres from 390,000 tons per year, to 17,000 tons.

Karl is the Editor of the Bay Journal.