Improving water quality with shorter corn, deeper roots

Driving across Minnesota in late September means passing acres and acres of towering corn. The golden brown stalks are an iconic sign of fall, but Professor Jeff Coulter is exploring a shorter version of the iconic corn plant to tackle a persistent challenge in agriculture - nitrogen runoff. 

Corn is a versatile crop and an important staple in the world food system. To grow efficiently and support high yields on less land, corn crops require sufficient amounts of nitrogen. Providing the plants with enough nitrogen at the right time and avoiding it washing away in the water has proven to be a challenging problem. Nitrogen pollution in water is detrimental to human health, can lead to environmentally harmful algae blooms, and nitrogen washed away means lost revenue for farmers. 

Researchers at the University of Minnesota have long explored practices to reduce nitrogen runoff, from precision nitrogen application, improved soil health, buffer strips, and cover crops, to name a few. But University of Minnesota Extension agronomist and Agronomy and Plant Genetics Professor Jeff Coulter is coming at the problem from another angle - short stature corn hybrids.

These shorter hybrids of corn have been seen as a promising crop for some time. The squatter stalks are better able to withstand high winds, farmers can more easily drive equipment through their fields to apply fertilizer or fungicides, and because the corn can be planted more densely, there’s potential for increased yield. Coulter is interested in a different aspect of these new hybrids, their larger and deeper root systems. 

Together with Jeff Vetsch, a researcher and soil scientist at the University’s Southwest Research and Outreach Center (SROC), and Paulo Pagliari and Fabian Fernandez, both Extension nutrient management specialists and professors in the Department of Soil, Water and Climate, they are examining how these root systems access and use nitrogen in the hopes of producing similar or greater yields with a smaller environmental footprint. 

“We are evaluating three short-stature corn hybrids and three standard hybrids, each at six different nitrogen (N) fertilizer rates applied preplant,” Coulter explains. “We are measuring leaf tissue nitrogen concentration, grain yield, grain moisture content at harvest, grain yield components, indices of nitrogen-use efficiency and economic net return. The short-stature corn hybrids are planted at a higher planting rate than the standard hybrid.”

If these short-stature corn hybrids can produce similar or greater net return for farmers, coupled with a lighter environmental footprint due to greater recovery efficiency of applied nitrogen fertilizer and possibly a lower nitrogen fertilizer requirement, “that is a win-win scenario,” he says. It’s unlikely these new hybrids alone will solve nitrogen runoff problems, but it adds another angle to tackle the complex problem in a way that benefits farmers and the environment. 

This story is adapted from a piece originally published in the Summer 2026 issue of Gleanings from the Department of Agronomy and Plant Genetics. Funding for this research was provided by the Minnesota Corn Research and Promotion Council. 

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