Growing corn is a major agricultural enterprise but not necessarily for eating: By Julie Peller Ph.D.

Green Junction

Growing corn is a major agricultural enterprise in parts of the United States. According to the USDA, nearly a billion bushels (1 bushel = 1.24 cubic feet) of grain corn were harvested in Indiana, accounting for 6.7% of the 14.9 billion bushels collected in 2024 in the entire United States. In 2023, about 43% of Indiana’s corn was used to make ethanol, a type of biofuel. According to the Indiana Corn Marketing Council, Indiana’s economy benefits from the 1 billion gallons of ethanol that are produced annually.

Most gasoline sold in the United States contains 10% ethanol (E10) by volume. The three general blends of gasoline are E10, E15, and E85. All car engines can run on E10, while only certain types (flex fuel vehicles) can use E85. The energy content and fuel efficiency of ethanol blends are lower than those of gasoline. The 1990 Clean Air Act and the 2007 Renewable Fuel Standard of the Energy Independence Security Act led to the addition of ethanol in gasoline to reduce certain pollutants from vehicle emissions. The production of biofuels in the US has increased more than fivefold in the past two decades.

A recent study by the World Resources Institute analyzed the environmental and societal harms of biofuels. Raising crops for biofuel (corn ethanol) reduces the land used for food production. Biofuel policies may lead to higher food prices, and this type of agriculture has worsened inequality for smaller farmers. The reliance on fertilizers for monocropping (growing the same crop on the same land year after year) impacts water quality, soil quality, and wildlife. The high use of nitrogen fertilizers leads to greater emissions of nitrogen oxides, a potent greenhouse gas that contributes to climate change, and nitrate runoff from farm fields. The study suggests “the Midwest has an opportunity to rethink the role that crop-based biofuels should play in the region’s future to better support people, nature and the climate.” Andi Anderson, of Indiana Ag Connection, wrote, “While Indiana’s ethanol industry helps many rural communities, ongoing discussions about its long-term impacts remain important for shaping sustainable agricultural policy.”

“In all things of nature there is something of the marvelous.” Aristotle

Julie Peller, Ph.D., is an environmental chemist (Professor of Chemistry at Valparaiso University). She has been writing a weekly column called The Green Junction for the past seven years and is helping to move the call of Laudato Si to action forward. Her research interests include advanced oxidation for aqueous solutions, water quality analyses, emerging contaminants, air quality analyses, challenges along the Lake Michigan shoreline (such as Cladophora, water, and sediment contaminants), and student and citizen participation in environmental work.