Controversial study argues corn better used as food than fuel

A controversial new study claims that using corn for biofuels comes with greater environmental costs and fewer benefits than using it for corn.

The study from researchers at the University of Illinois and Urbana-Champaign has been published in the journal Earth’s Future. It aims to determine whether corn is better utilised as a biofuel or as a food source, addressing the food vs. fuel debate that has persisted ever since ethanol came into use.

Authors Praveen Kumar, civil and environmental engineering professor at University of Illinois, and Meredith Richardson, a graduate student, say that food and fuel use of corn has been quantified and compared in terms of economics of the entire production system for the first time.

"The critical zone is the permeable layer of the landscape near the surface that stretches from the top of the vegetation down to the groundwater," Kumar said in a statement. "The human energy and resource input involved in agriculture production alters the composition of the critical zone, which we are able to convert into a social cost."

To compare energy efficiency and environmental impacts of different corn uses, the researchers inventoried the resources required for corn production and processing, then determined the economic and environmental impact of using these resources. This was all defined in terms of energy available and expended, and normalised to a cost in US dollars.

"There are a lot of abstract concepts to contend with when discussing human-induced effects in the critical zone in agricultural areas," Richardson said. "We want to present it in a way that will show the equivalent dollar value of the human energy expended in agricultural production and how much we gain when corn is used as food versus biofuel."

Their results show that in monetary terms the net social and economic worth of food corn production in the US is $1,492 per hectare, versus a $10 per hectare loss for biofuel corn production.

“One of the key factors lies in the soil,” Richardson said. The study took into account both long0term and short-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.” Richardson said.

“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."