West Tennessee farmers are taking the first steps toward identifying switchgrass varieties suited for the Mid-South.
In late May, producers Tony Brannon and Andy Holt planted 5-acre test plots of EG 1101 and EG 1102, switchgrass varieties from Ceres, Inc., a California-based developer and marketer of switchgrass and high-biomass sorghum.
Data on switchgrass will be collected from these two locations and four others in west Tennessee this season. “Our goal is to learn first-hand how to manage this new crop, and then to use that knowledge to facilitate the development of the bioenergy industry in Tennessee,” said Brannon, a Puryear, Tenn., farmer who is also dean of the School of Agriculture at Murray State University.
“These alternative crops can give farmers new options and bring new value-added opportunities to the region,” added Holt, who is a west Tennessee livestock producer and is actively involved in Tennessee Farm Bureau.
Both Holt and Brannon are members of the 25Farmer Network, a group of farmers from 21 west Tennessee counties contractually involved with Memphis Bioworks AgBio to develop projects related to growing and processing alternative crops.
A perennial crop, switchgrass is widely considered an ideal raw material for non-food, low-carbon biofuels, biopower and other bioproducts.
Researchers are working on ways to reduce the cost of special enzymes needed to convert biomass to ethanol, which would pave the way for cellulosic ethanol plants and more acreage dedicated to cellulosic crops like switchgrass.
Currently, corn grain is the primary feedstock for producing ethanol in the United States. It does not require the use of high-cost enzymes.
Brannon runs a family farm of about 450 acres of corn, soybeans and wheat and 50 head of beef cattle on 150 acres of pasture.
Five years ago, Brannon planted and produced 15 acres of switchgrass under a grant with the University of Tennessee for a biofuel study. His experience with the crop has been positive, with yields of 6.5 tons in 2008.
The crop has proven versatile too. Brannon sees three potential uses from his switchgrass crop — as forage for his cattle if a biomass market is not available, a seed crop of the Alamo switchgrass variety and biomass production if there is a market.
The 5-acre variety plot was planted May 29 with a Sunflower no-till drill into ryegrass stubble at 7.5-inch spacing. “The production guideline says you need about 50 percent bare soil, and that’s about what we had,” Brannon said. “It’s a very sensitive crop as far as establishment is concerned. Thankfully, we had a good shower two days after we drilled, and we’ve had some good ones since.
“One of the biggest benefits of switchgrass is that you’re out some nitrogen costs, about 60 units per acre, but all the other nutrients recycle — when the crop senesces, the nutrients go back into the soil. Soil tests after four years on the 15-acre switchgrass field were essentially the same as we had going in.”
Brannon says production costs for switchgrass are minimal, “but even if you went with the more intensive management to get forage, seed and biomass crops, it would require only one additional application of nitrogen fertilizer. I put 60 units on in the spring and 60 units in the fall.”
Brannon harvests switchgrass seed with a Gleaner combine with a small-seed kit and harvests switchgrass biomass with traditional hay harvesting equipment which produces a round bale.
“I’m convinced that traditional baling is not the best way to harvest cellulosic material. In order for switchgrass to take off in west Tennessee, you have to work on transportation, harvesting and logistics. There needs to be some harvesting technology development that allows that process to become more efficient.”
Transportation problems could be minimized by pelletizing switchgrass for biomass, “because it’s so much easier to transport that way. It’s not going to all be grown near the cellulosic plant. As we develop the crop, there are going to be some investment opportunities for those willing to do that.”
Bales of switchgrass may have to be stored on the farm for several months following harvest, according to Brannon. So far, he has not experienced degradation of bales.
Brannon says the 25Farmer Network is working on finding end-users for the variety plots going in this season. As for Brannon’s 15-acre plot, “We’ve made several inquiries and at this point we don’t have an end user identified. We’ll probably cycle our first harvest through some beef cattle.”
Brannon doesn’t see switchgrass taking over cropland currently dedicated to corn, soybeans and wheat. “I think it’s a supplemental crop. We’re in different economics than we were four years ago with the grain markets.”
Hillary Spain, coordinator of the 25Farmer Network, points out that switchgrass is just one of the opportunities being pursued by the farmers. “Our work with Ceres is one great example of this, where we have an opportunity to find out what works in west Tennessee with a leading commercial seed provider.”
Frank Hardimon, director of sales for Ceres’ energy crop seed brand, Blade Energy Crops, says the partnership between Memphis Bioworks Foundation, Ceres and the Tennessee Department of Agriculture “has facilitated an important connection with very capable farmers who share our goal of exploring the potential for energy crops in west Tennessee.”
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