Food vs. Biofuel: The Energy Efficiency Duel
Gelfand, I., Snapp, S.S. and Robertson, G.P. 2010. Energy efficiency of conventional, organic and alternative cropping systems for food and fuel at a site in the U.S. Midwest. Environmental Science and Technology 44: 4006-4011.
To initiate the filling of this data void, Gelfand et al., as they describe it, "used 17 years of detailed data on agricultural practices and yields to calculate an energy balance for different cropping systems under both food and fuel scenarios," comparing one forage and four grain systems in the U.S. Midwest that included "corn-soybean-wheat rotations managed with (1) conventional tillage, (2) no till, (3) low chemical input, and (4) biologically based (organic) practices, and (5) continuous alfalfa," where they "compared energy balances under two scenarios: all harvestable biomass used for food versus all harvestable biomass used for biofuel production."
Overall, the three researchers report that "energy efficiencies ranged from output:input ratios of 10 to 16 for conventional and no-till food production and from 7 to 11 for conventional and no-till fuel production, respectively."
Gelfand et al. say that their analysis "points to a more energetically efficient use of cropland for food than for fuel production," and that the large differences in efficiencies attributable to the different management techniques they evaluated suggest that there are "multiple opportunities for improvement." Thus, as the debate over the desirability of using good cropland for biofuel production continues to rage, it is becoming ever more evident that food should be the world's priority.