 A big boost to the Iowa and U.S. economy provided by corn farmers. A new study by the National Corn Growers Association says that American corn growers were responsible for a $152 million contribution to the U.S. economy in 2023. The report looked at the number of ways corn growers helped shape the economy, including economic output, contributions to the gross domestic product, tax revenues, labor income, employment statistics, and more. Number two.