Unlocking the Secrets of Root Systems: How UMN Researchers Are Using Minirhizotron Technology to Advance Sustainable Agriculture

In the pursuit of more sustainable and resilient agricultural systems, understanding plant root systems is just as crucial as studying their above-ground growth. Researchers at the University of Minnesota’s Sustainable Cropping Systems Lab and the Intermediate Wheatgrass Breeding Lab are leveraging cutting-edge root imaging technology to better understand the underground dynamics of intermediate wheatgrass, also known as Kernza. Their work is shedding new light on how root traits correlate with plant productivity and sustainability, offering insights that could shape the future of perennial grain agriculture.

The Research Team and Their Mission

Cole Schiller, a researcher and lab technician, and Brooke Burnhardt, a Ph.D. student, are part of a team dedicated to studying the root systems of perennial crops. Their research focuses on the SPARK (Spaced Plants and Rhizotron in Kernza) experiment—an initiative that utilizes minirhizotron imaging to examine the root structures of different Kernza genotypes. The goal? To identify root traits that contribute to both higher yields and increased carbon sequestration, making Kernza a more viable and sustainable crop for commercial agriculture.

“The purpose of this research is to conduct root phenotyping and genetic characterization of root traits,” Brooke explained. “We want to see how root traits correlate with above-ground yield and other physiological factors like chlorophyll fluorescence, which is dependent on water and nutrient uptake.”

How Minirhizotron Technology is Transforming Root Research

Traditional root analysis methods are labor-intensive and disruptive to the plants. The minirhizotron camera system, however, allows researchers to take images of roots in situ without disturbing the soil structure. These images are then processed using machine learning software such as RootPainter and RhizoVision to extract valuable root trait data.

“We take images from the minirhizotron camera and process them through RootPainter, which is an open-source machine learning software,” Brooke noted. “From there, we get black and white images that can be analyzed in RhizoVision, which provides detailed root metrics such as root length, diameter, and branching patterns.”

The ability to automate root tracing significantly reduces the time and labor required for root analysis, allowing the research team to focus on larger-scale studies with more extensive data collection.

Data Collection and Field Challenges

The SPARK experiment involves approximately 160 rhizotron tubes installed in research plots, capturing root images at three key points in the growing season: early spring, post-harvest, and late fall after the first major freeze. This timeline helps researchers track root development across different physiological stages of the plant’s growth cycle.

Beyond data collection, maintaining the integrity of the rhizotron tubes presents challenges. From weather exposure to curious wildlife—particularly coyotes that enjoy chewing on foam tube covers—the team has developed various workarounds to protect their equipment. “We’ve tried using rubber caps, painting tubes black to block light, and even placing bricks over the tubes to keep them secure,” Cole said.

Implications for Agriculture and Sustainability

One of the key goals of this research is to improve the sustainability of Kernza by breeding for both high-yielding plants and those with extensive root systems that contribute to carbon sequestration. The insights gained from this study could help agricultural producers optimize Kernza cultivation while supporting environmental sustainability efforts.

“Companies interested in carbon offsets might find Kernza appealing due to its root biomass and ability to sequester carbon,” Cole pointed out. “If we can better understand the relationship between root growth and productivity, we can make more informed breeding decisions that benefit both farmers and the environment.”

What’s Next?

The team plans to continue their root imaging efforts for at least another year before publishing their findings, with an expected release in late 2026 or early 2027. They also hope to expand the applications of their research by exploring additional traits that could further optimize Kernza’s performance.

In the meantime, they remain open to learning from other researchers and sharing their own best practices. Their advice for fellow scientists using minirhizotron technology? Take extra care in installation, ensure proper light blocking, and leave enough space in research plots for easy equipment access.

With new advancements on the horizon—including an automated root imaging system currently under development—analyzing underground plant growth is becoming faster, more efficient, and more insightful than ever before. As this research progresses, the knowledge gained will continue to push the boundaries of sustainable agriculture, one root at a time.