What do you do with rolling prairie and cleared timber ground that's been judged too erodible for row-crop production?
For a group of south-central Iowa farmers and landowners, the answer may lie in switchgrass, a grass that was there when their ancestors arrived.
Believing that the Conservation Reserve Program (CRP) is not a long-term solution to their farm income situations, they've concluded that switchgrass is the right crop. Now they have to figure out how to turn it into a profitable enterprise.
For the past two years, they've been studying the feasibility of using it to co-fire a power plant. The economics don't look very promising, but studies in other areas suggest that switchgrass may be a viable crop for other uses.
For example:
* Studies in Nebraska and Indiana suggest that it could be used to produce as much as 500 gallons of ethyl alcohol per acre.
* Canadian researchers are looking into using it for paper production to replace some of the fiber now supplied by wood pulp.
"It's a crop with many potential uses and, more importantly, one we can grow on highly erodible land with little risk of soil loss," says Don Clark of Centerville, IA, one of the cooperating landowners. "All we have to do is find the best ways to use it and develop a market."
Switchgrass is a native American prairie grass that grows tall and coarse. A bunch grass rather than a sod former, it combined with numerous other grasses and plant species to form the original prairie in the area. Switchgrass produces a heavy fibrous root system that prevents soil erosion, so it has been used to seed down a lot of CRP acres.
When harvested at the end of the growing season, its coarse stems and leaves contain approximately as much useable energy per pound as coal.
That's what got Chariton Valley Resource Conservation and Development, Inc., Centerville, and area farmers interested in the energy-use possibilities of switchgrass. Also involved in the project are USDA, the U.S. Department of Energy, the Iowa Leopold Center for Sustainable Agriculture, and other agencies and individuals. John Deere and Vermeer have provided free harvesting equipment.
Key to the entire effort was cooperation from Alliant Energy Co., Cedar Rapids, which agreed to use switchgrass to co-fire its Ottumwa Generation Station.
So far, all the switchgrass used in the study has been produced on CRP land, harvested with USDA's blessing and donated to the cause by landowners.
The hope, says Jim Cooper, with Chariton Valley RC&D, is that farmers can earn $200/acre in income from switchgrass. Cooper says that properly managed switchgrass will yield at least as much as other hay crops on comparable soils with comparable management. To do that, the crop will have to be managed with no less intensity than a good stand of alfalfa or other forage.
"We're talking about paying attention to seeding rates, use of herbicides or other crops to keep down weeds while the switchgrass is becoming established, and the use of fertilizer to boost yields," says Clark.
Clark has seeded 130 acres of his CRP ground to switchgrass. Some stands are going on four years old, while the youngest were seeded last spring. He and the other growers studied research from Kansas State University and other ag schools to learn how best to establish stands. But much of what they learned was by trial and error.
"And we're still learning," says Clark.
His best stands have come from no-till seeding with a drill after killing existing sod with Roundup. A later application of atrazine helps eliminate in-season weed pressure while leaving the switchgrass untouched.
Clark tried seeding 5 lbs/acre at first, largely because seed prices were high and he wanted to hold down costs. Since then, he's gone with higher rates, usually 10 lbs/acre or more.
"Seed prices have come down and you get a better stand so you need less herbicide later on," he explains.
Yields vary according to the age of the stand and management. However, yields of 5-7 tons/acre or more are reasonable in a one-cut system, Cooper says. Harvesting and handling expenses are similar to those for other forages.
Clark estimates that long-term expenses will come in around $100/acre, assuming steady seed, fertilizer, cutting and baling costs.
To net $200/acre from a 5-ton yield with $100/acre in expenses, hay prices will have to be at least $60/ton. That's at the top end of current prices for grass hay, Cooper points out. Higher yields will improve the picture, but may not be enough.
Cooper says coal is being delivered to the power plant at around $15/ton. That leaves a $45 price deficit, and the hay still has tobe delivered and chopped so it will feed evenly into the boiler.
State and federal renewable energy credits and mandates will help make switchgrass a little more economically appealing as a renewable fuel. But unless they are increased or the price of coal goes into a steep climb, it may not be enough.