By Fae Holin
Managing Editor, Hay & Forage Grower
If grown in rotation with corn, alfalfa could be a biofuel crop destined to help attain the Renewable Fuel Standards' biofuel production goal of 36 billion gallons by 2022. But a number of challenges must be overcome before an alfalfa-corn production system – producing cellulosic biomass for biofuels and livestock feed – can become reality. So said speakers and others at a workshop in Johnston, IA, last week.
“Alfalfa/Corn Rotations for Sustainable Cellulosic Biofuels Production” was hosted by the National Alfalfa and Forage Alliance (NAFA) and National Corn Growers Association. Sponsored by alfalfa seed companies and seed producer organizations, the workshop speakers included USDA and university researchers as well as representatives from four biofuel companies.
Two-year rotations of alfalfa with corn could supply cellulosic biomass for biofuels as well as food and feed, improve corn yield by 5-15% with alfalfa’s soil-holding properties and nitrogen-fixing capabilities, and reduce greenhouse gas emissions, speakers contended. Research on equipment that separates alfalfa leaves and stems, using stems as biomass and leaves as high-protein feed, have been in the works for years. See “Alfalfa: Queen of Biomass, Too?”
But speakers and participants acknowledged several major obstacles. Research funds and additional data on alfalfa are needed. Corn growers would have to give up the convenience of continuous corn and either custom hire or buy forage harvesting equipment. Equipment used to harvest alfalfa would likely need redesigning. Agronomic, environmental, logistical, conversion, economic and policy issues would all need further study.
One speaker didn't think pairing alfalfa with corn was a good idea. “It's an issue of relative effort. There are certain limitations as to what is happening with corn (yields),” said Jeffrey Steiner, the USDA-ARS national program leader for biomass production systems and an agronomist. Rather than linking alfalfa with corn, Steiner suggested that participants look at coupling it with another crop or developing a co-product from it, such as high-value protein.
“It's not going to stand just on corn,” Steiner said. “We have to think about what grows where and what comes from where. And we have to set our minds as to what is already being used from those lands.”
Hans Jung, USDA-ARS researcher, believes the alfalfa-corn rotation will work. “Here in the Midwest we know we are standing on some of the best farmland in the country. So it's our opinion that the Corn Belt can't be excluded from this command to produce biomass.” He estimates that, if just 10% of Minnesota's corn-soybean rotation acreage were converted to an alfalfa-corn rotation, enough cellulosic biomass could be supplied to produce 300 million gallons of ethanol per year.
One biofuel company spokesperson was asked what he thought of the viability of an alfalfa-corn rotation to produce biofuel. “I saw a lot of good information yesterday,” answered Tom Robb, Abengoa Bioenergy Corp. manager for institutional relations. “But what are the economics of the system? I don't know if it is workable or not. I applaud your efforts for trying to put this together, and I would like to see the effort continue. But to have an opinion as to whether it would fly or not? I don't have sufficient information.”
A steering committee made up of workshop participants will develop an action plan to further the research on alfalfa as a biofuel feedstock, according to Beth Nelson, NAFA president. The workshop proceedings will be available at www.alfalfa.org.