A team at the University of Nebraska–Lincoln is exploring sweet sorghum ethanol as a future income source for dryland agriculture in western Nebraska.

Sweet sorghum is a cultivar of sorghum primarily developed for the harvest of juice. Due to its high sugar content and stability during periods of drought, researchers have identified the crop as a potential ethanol feedstock crop on non-irrigated farmland in western Nebraska. Ethanol feedstocks are the plant materials which can be converted to ethanol. In this case, the sugar syrup from sweet sorghum stalks would be fermented to make ethanol.

Corn currently serves as the leading feedstock for ethanol production in the U.S. For sweet sorghum to compete with corn for ethanol production, not only must it be more lucrative than corn for farmers to produce, but it also must be more economical than corn for ethanol plants to process. Considering factors such as yield and the cost of processing, researchers estimate that the current sorghum to ethanol pathway is a barely break-even prospect in western Nebraska.

“Under the typical conditions considered, there are insufficient benefits to farmers and ethanol plants to make the sweet sorghum ethanol pathway an attractive economic opportunity,” said Richard Perrin, Jim Roberts Professor in the Department of Agricultural Economics. However, according to Perrin, the researchers found that there are a few potential considerations that would improve the viability of the pathway.

Currently, the U.S. Renewable Fuel Standard (RFS) mandates consumption of specific levels of renewable fuels made from various categories of feedstocks. Under the markets created by the RFS, ethanol plants would be almost certain to obtain a premium for sweet sorghum ethanol compared to corn ethanol. The current level of that premium makes the pathway much more economical. However, according to the researchers the volatility of this market premium and the contentious political opposition to the RFS make this benefit risky.

Another consideration which could increase the potential of the sweet sorghum ethanol pathway, is an increase in yields. A separate $13.5 million multi-institutional research project led by Nebraska may provide the necessary yield increases. That effort aims to improve sorghum as a sustainable source for biofuel production

“If the research efforts raise biomass yields by 20-30 percent, or shows that yields are actually 20-30 percent higher than our estimate, the benefits to both the producer and the ethanol plant would be sufficient to make adoption of sweet sorghum for ethanol a sustainable possibility,” Perrin said.

Joining Perrin in this research effort were Lilyan Fulginiti, professor in the Department of Economics, Ismail Dweikat, professor in the Department of Agronomy and Horticulture, and Subir Bairagi, post-doctoral fellow at the International Rice Research Institute.

Details of this research were reported in the January issue of the Journal of Agricultural and Resource Economics.