Corn: biofuel or food?

Renewable biofuels are so environmentally warm and fuzzy. Plant the corn, grow it in the sunshine and fresh air, harvest it and then turn it into ethanol for use as fuel. Really, you can just about hear the birds singing. But is this the most economically and environmentally advantageous way to use corn? How about using corn as a food?

To compare the energy efficiency and environmental impacts of corn production and processing for food and for biofuel, researchers from the University of Illinois inventoried the resources required for corn production and processing, then determined the economic and environmental impact of using these resources — all defined in terms of energy available and expended, and normalised to cost in US dollars.

They found that the net social and economic worth of food corn production in the US is $1492/ha, whereas biofuel corn production resulted in a $10/ha loss.

The team assessed the energy required to prepare and maintain the landscape for agricultural production for corn and its conversion to biofuel. Then they quantified the environmental benefits and impacts in terms of critical zone services, representing the effects on the atmosphere, water quality and corn’s societal value, both as food and fuel.

Civil and environmental engineering professor Praveen Kumar and graduate student Meredith Richardson published their findings in the journal Earth’s Future.

“One of the key factors lies in the soil,” Richardson said. “The assessment considered both short-term and long-term effects, such as nutrients and carbon storage in the soil.

“We found that most of the environmental impacts came from soil nutrient fluxes. Soil’s role is often overlooked in this type of assessment, and viewing the landscape as a critical zone forces us to include that.”

“Using corn as a fuel source seems to be an easy path to renewable energy,” said Richard Yuretich, the NSF program director for Critical Zone Observatories. “However, this research shows that the environmental costs are much greater, and the benefits fewer, than using corn for food.”