Quinn Dishes Dirt on Roots
Published: Friday, January 16, 2026
Some corn roots are vertical while others are horizontal. In the world of corn, does the root angle matter when it comes to yields?
According to Purdue University Extension corn specialist Dan Quinn, the answer is yes.
Quinn spoke at a private applicator recertification program last Thursday in Wakarusa.
Purdue has partnered with Beck's Hybrids on research looking at corn root angles. The research compared hybrids with varying root angles, vertical and horizontal.
"The root architecture does differ," Quinn said. "Hybrids do differ in root size and root architecture."
In research at the University of Illinois, plants with vertical roots had higher yields when phosphorus and potassium were banded directly into the root zone. However, plants with horizontal roots did better with a broadcast fertility system.
Quinn said it's not a matter of which hybrid is better but rather which hybrid—vertical or horizontal—performs better with your fertilizer placement.
The Purdue research trial began in 2024 at two locations, West Lafayette and Wanatah.
"The big reason I chose these locations ... is because they are very different when it comes to soil types," he said.
The Wanatah site, at the Pinney Purdue Research Farm, has sandy soil with low fertility, whereas the West Lafayette site has more productive soil, with higher organic matter.
The fertilizers used in the research trial were Super U (urea) and Mesz, both dry forms. The fertilizer was applied, strip-tilled below the root zone, at a rate of 200 pounds of nitrogen per acre and 20 pounds of sulfur per acre.
Nutrient amounts were the same for both banded and broadcast applications.
The hybrids were Beck's 6184 and 6414, both of which have vertical roots, and 6152 and 6274, which are classified as horizontal.
According to Quinn, one finding was that hybrids with higher root surface area have higher nutrient uptake. This is true regardless of root angle and fertilizer system (banded or broadcast).
Preliminary results from 2024 show that the broadcast fertilizer outperformed the strip-till application with respect to yields.
"We did see some hybrid differences, predominantly in the horizontal root system hybrids," he said. "We're seeing a little bit more of a benefit from that broadcast fertility application."
Vertical hybrids also performed better with broadcast fertilizer but not as well as horizontal hybrids.
In the 2025 research trial, the West Lafayette location showed less of a difference between the hybrids.
Quinn plotted the data on a graph.
"If you look at the points, there's no statistical difference, but (when) you look at the trend between the two points, the broadcast system is doing a little bit better when we look at average yields in the horizontal root systems," Quinn said. "We're seeing a little stronger indication in 2025 that the vertical root systems are doing a little bit better when we band that fertility. Horizontal root systems are doing a little bit better when we broadcast that fertility."
At the Pinney Purdue farm, the Purdue corn specialist saw a stronger difference, with horizontal hybrids outperforming the vertical hybrids.
"We're seeing some indications ... that these hybrids are responding a little bit differently to these applications of fertility," Quinn said.
He added that there was virtually no difference in yield between the two root systems with no fertilizer applications.
The take-away point is that hybrids perform differently, and growers should understand how a vertical or horizontal hybrid would best fit in their respective management system.
Quinn said the data is preliminary. The research trial will continue for another two years. He said future research will look at starter fertilizer and liquid fertilizer applications.
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