Switchgrass (Panicum virgatum) has been identified as a promising bioethanol feedstock with good net energy and GHG (greenhouse gas) balances. A recent study by the team from the United States Department of Agriculture-Agricultural Research Service (US DA-ARS) revealed that the net energy yield and GHG reduction from switchgrass-based ethanol may be much greater than previously estimated. In their study, the researchers mentioned that previous net energy estimates were based on small research plots of less than 5 square meters. Based on field trials in larger plantation areas (30,000 square meters to 90,000 square meters) in marginal farmlands “across wide precipitation and temperature gradients in the mid continental United States”, the results showed that switchgrass yields a 540% net energy. The switchgrass biomass and net energy yields were said to be 93% higher than previous estimates. The estimated GHG emissions were also found to be 94% lower than gasoline. Energy sustainability and biofuel potential of switch grass could be further enhanced by “improved genetics and agronomics”. More information about the study can be obtained from their paper published in the Proceedings of the National Academy of Sciences (PNAS) (URL above)..