Researchers with the University of Tennessee Biofuels Initiative (UTBI) are watching more than 1,000 acres of improved switchgrass varieties to find out if they’ll grow better, stronger or faster than Alamo, a standard variety.

The varieties were planted this spring as part of a U.S. Department of Energy project designed to help make bioenergy production from renewable resources more efficient, cost-effective and sustainable. Sam Jackson and Nicole Labbe, biofuels researchers at the university, are heading up the project team that also includes Extension biofuels specialists and partners at Ceres and Dupont Danisco Cellulosic Ethanol (DDCE). They planted the 1,000-plus acres on farms in nine eastern Tennessee counties, and will compare those fields with a different 1,000 acres planted to Alamo. A total of nearly 6,000 acres of switchgrass have been established on private farms as part of the UTBI farmer incentive program.

The idea is to improve switchgrass yields to help meet the 16 billion gallon level of production required by the national Renewable Fuels Standard (RFS) for cellulosic biofuels by 2022. Improving per-acre biomass yields from dedicated energy crops like switchgrass will significantly reduce the land required to meet the RFS goals.

The improved varieties were developed by the biotechnology company Ceres and are sold under the company’s Blade Energy Crops brand as EG 1101 (an improved Alamo variety) and EG 1102 (an improved Kanlow variety). The Genera Energy/DDCE demonstration-scale biorefinery in Vonore, TN, will process the grass into cellulosic ethanol.

Jackson says the project will have four phases: comparing large-scale production of the varieties, analyzing their chemical and structural characteristics, evaluating preprocessing techniques at Genera’s Biomass Innovation Park in Vonore, and measuring the ethanol yield of the varieties through the demonstration-scale biorefinery.

The scale of the acreage will also allow for assessment of the environmental and economic sustainability of the different varieties. Farmers and researchers should gain useful information on seedstock performance, including disease and drought resistance, tolerance to humidity and other agronomic variables.

"These are the largest acreages to be planted for growth comparisons on private farms in the nation,” Jackson says. “The size of the project is necessary to adequately test and demonstrate the supply chain with local farm producers. We hope to prove the practicality of producing improved varieties of dedicated energy crops while providing a hands-on opportunity for farmers to be engaged in the development of a new biobased energy industry.”

“We are hearing reports of good establishment and healthy stands from the new seed varieties,” says Frank Hardimon, Ceres sales director. “This is a reflection of both improved genetics and high seed quality as well as excellent support from University of Tennessee agronomists.” He notes that the demonstration project will also help guide the development of the next generation of varieties and traits fine-tuned to the DDCE conversion processes. “We expect to make the same type of leaps in crop performance that seed companies have made in traditional crops. We’re just scratching the surface of what’s possible,” he says.

Kyle Althoff, director of feedstock development at DDCE, notes that this project provides a great opportunity for collaboration across the value chain for advanced biofuels. “By comparing the cellulosic ethanol conversion yields of these different varieties grown by local farmers, we will have a commercial demonstration of the economical, technological and environmental impacts of each variety,” says Althoff. “It is integral for the biofuels industry to understand the effects that such variables have from the point the seed is planted through to the actual conversion into ethanol.”

The state initially invested $70 million in 2007 to establish the UTBI for the construction of a demonstration-scale biorefinery as well as for farmer incentives to grow the crop and for research to help develop a new farm-based bioenergy industry for Tennessee. UTBI’s leaders estimate that Tennessee farmers could sustainably produce enough switchgrass by 2025 to produce more than a billion gallons of ethanol annually on 1 million acres without displacing the production of food and fiber crops.

Read more about the Tennessee initiative.