A five-year study involving farms in Nebraska, North Dakota and South Dakota examined the net energy output, greenhouse gas emissions, biomass yields, agricultural inputs and estimated cellulosic ethanol production from switchgrass grown and managed for biomass fuel University of Nebraska-Lincoln said Tuesday in a release.

The study found that the prairie grass produces 540 percent more energy than needed to grow, harvest and process it into ethanol.

Ken Vogel, a U.S. Department of Agriculture-Agricultural Research Service geneticist in UNL's agronomy and horticulture department, said the study also found greenhouse gas emissions from cellulosic ethanol made from switchgrass were 94 percent lower than estimated greenhouse gas emissions from gasoline production.

The findings were published in Proceedings of the National Academy of Sciences.