Circular Economy That Reimagines Corn Agriculture

Adapting Corn to Environmental Challenges

Grain production, including corn production, in the United States is highly efficient in terms of labor, cost and land, yet generates massive nitrogen losses that end up in our waterways and generate greenhouse gas (GHG) emissions that contribute to climate change. For example, excess nitrogen fertilizer contributes to six percent of total U.S. GHG emissions. These fertilizer losses costs farmers billions of dollars every year.

The CERCA (Circular Economy that Reimagines Corn Agriculture) project, led by the U.S. Department of Agriculture-Agricultural Research Service along with 13 university research partners and helmed by Dr. Edward Buckler, aims to transform U.S. grain farmland into a net-negative component of the circular bioeconomy – using renewable or regenerative inputs to produce food. Their research seeks to develop a corn variety that has less nitrogen demand, recycles nitrogen at the end of the season, and tolerates colder temperatures, so it can be planted earlier in the growing season when nitrogen is plentiful in the soil. This adapted crop will possess increased starch yields, greater climate resilience and require less fertilizer.

Developing Corn Crops Requiring Fewer Inputs

While corn is an efficient starch producer, the protein it produces is of low nutritional quality and, for many of the harvested crop’s uses, not needed. However, this kernel protein requires tremendous fertilizer inputs to produce.

The CERCA project is using a combination of modeling, genetics, physiology and agronomy to reduce fertilizer needs while maximizing starch yields by optimizing the plant’s ability to recycle nitrogen. To achieve these goals, the researchers are focusing on two strategies – the first taps into the higher level of natural nitrogen and light available in spring, and the second reduces the protein in corn grain, which lowers nitrogen demand and provides an opportunity for the plant to return nitrogen to the soil for the next season.

For the crop to use the natural nitrogen available in spring, it needs to be planted a few weeks to a month earlier than it currently is, but this risks damage from frost and cold temperatures. Corn and its wild relatives have genetic variation that can allow cold tolerance, and this project is finding and testing this variation to enable earlier planting, which would have additional benefits to yield and planting and harvesting flexibility. In addition, the project also aims to reduce the low nutritional quality protein in corn and foster the plant’s ability to return unused nitrogen to the soil at the end of the season by tapping into the genetics found in corn’s perennial relatives. Overall, the aim is to reduce nitrogen losses by over 50%, which would reduce fertilizer requirements, water pollution and GHG emissions by similar levels or more.