Corn-based ethanol may offer significantly lower greenhouse gas emissions than previously believed.
This realization comes following the release of a recent study performed by U.S. Department of Agriculture researchers showing that corn grown using no-till methods may sequester larger amounts of carbon more deeply than previously known.
The study, which was published in BioEnergy Research, revealed that corn grown over a 10-year period using no-till practices sequesters carbon in the soil down to depths as far as 59 inches under the surface. Previous studies, which looked at depths of less than 11 inches or so, did not take into account carbon sequestration below tillage depths. In doing so, their findings missed more than 50 percent of the increase in soil organic carbon below that depth.
With this new information, models used to calculate and predict the environmental benefits or liabilities of corn production will be able to better reflect the actual impact. As the study shows an average annual increase in soil carbon of approximately 1.2 tons of carbon per acre, new models will likely show more accurately how corn-based ethanol offers a tremendous greenhouse gas emissions reduction when compared to petro-fuels.
"The findings of this study are important in that they demonstrate a previously overlooked environmental benefit of corn production in general and of corn-based ethanol in specific," said National Corn Growers Association Corn Board member Keith Alverson. "Estimates of the greenhouse gas savings corn offers over petro-fuels will undoubtedly show a more significant savings once data of this nature is factored into the overall analysis.
Farmers are working harder every day to produce food, fuel and fiber sustainably as they actually improve the land through their growing practices. As scientists expand the pool of data, the positive impact of the biofuels produced from their crops becomes clearer also."
Soil organic carbon and its sequestration are important, because they affect both soil fertility and greenhouse gas fluxes.
The study, which also looked at switch grass, was the longest on-going effort to look at carbon sequestration by these two crops.
As with all scientific data, it is important to realize that this is one study with one set of conditions. Others soil conditions need to be evaluated for a further understanding of the variables impacting SOC and sequestration.