Relationships between corn plants and nitrogen fixing bacteria on an organic farm

Ceres Trust Research Grant

Principal Investigator: Carrie K Young, Ph.D., Research Director, Michael Fields Agricultural Institute, PO Box 990 East Troy, WI 53120. Resigned from Michael Fields Agricultural Institute December 2012

Report Author: Allison Pratt-Szeliga

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Corn requires large quantities of nitrogen for its growth. Commercial corn production relies on substantial inputs of synthetic fertilizer. Overuse of synthetic fertilizer causes the contamination of surface and ground waters. The hypoxic zone in the Gulf of Mexico shows the extent of this pollution. Dependence on inorganic fertilizer can lead to soil degradation, as well. Farmers who use synthetic fertilizer are subject to fluctuating and ever- increasing fertilizer prices, primarily because it is derived from natural gas. Worldwide, many farmers cannot afford synthetic fertilizer. In the near future, agricultural production needs to decrease its reliance on inorganic fertilizer. Healthy soils and organic fertilizers are part of the solution, but biological nitrogen fixation also has the potential to displace synthetic fertilizer use.

The relationship between legumes and nitrogen-fixing bacteria is well understood. These bacteria fix atmospheric nitrogen that would otherwise be unavailable to the plant. Now there is increasing evidence that many non-leguminous species have the ability to cooperate with soil microorganisms to obtain atmospheric nitrogen. The objective of our research is to determine the potential of corn to fix nitrogen biologically. We are investigating several diazotrophic bacteria and how they interact with various breeding lines and seed treatments.

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