According to Biofuels Business, sweet potatoes yielded two to three times the carbohydrates for ethanol production as field corn, research by the United States Department of Agriculture (USDA) Agricultural Research Service (ARS) found. ARS released a report on the findings today. Scientists received similar results with tropical cassava.
The research found that sweet potato carbohydrate yields were similar to the lower limits of those produced by sugarcane, the highest-yielding ethanol crop. Another advantage for sweet potatoes and cassava is that they require much less fertilizer and pesticide than corn, the ARS said.
Lew Ziska, a plant physiologist at the ARS Crop Systems and Global Change Laboratory in Beltsville, Maryland, U.S., performed the study with colleagues from Beltsville and at the ARS National Soil Dynamics Laboratory in Auburn, Alabama, U.S.
The disadvantages to cassava and sweet potato were higher start-up costs, particularly because of increased labor at planting and harvesting times. Further studies are needed to get data on inputs of fertilizer, water, pesticides and estimates of energy efficiency. Overall, the data indicate it would be worthwhile to start pilot programs to study growing cassava and sweet potato for ethanol, especially on marginal lands.