FAYETTEVILLE, Ark. — Larry Purcell might be the most highly educated and scientifically cited bicycle mechanic in America.
With certainty, the recently retired Distinguished Professor of crop physiology for the University of Arkansas System Division of Agriculture has the admiration of Southern soybean breeders.
By John Lovett
University of Arkansas System Division of Agriculture
Arkansas Agricultural Experiment Station
Purcell, who pioneered agricultural research using drones and digital cameras to document genetic differences in soybean, was presented a Lifetime Achievement Award at the 2024 Southern Soybean Breeders Tour in Memphis. He retired in February, after more than 30 years with the Division of Agriculture and the Dale Bumpers College of Agricultural, Food and Life Sciences, as a Distinguished Professor and the Altheimer Chair for Soybean Research.
“I’ve received my share of awards over the past 30 years, but I’d say this is probably the most meaningful to me because it came from a group that I’ve been intimately involved with and have tremendous respect for,” Purcell said. “I’m not a soybean breeder, but some of my most impactful research has been in association with soybean breeders and geneticists.”
Purcell conducted research through the Arkansas Agricultural Experiment Station, the research arm of the Division of Agriculture, focusing on the genetic differences in a plants’ use of water and nitrogen.
His research portfolio is rich with studies on how nitrogen fixation in soybean is impacted by drought, genetic differences among genotypes, and a soybean plant’s response of nitrogen fixation by drought. Nitrogen fixation is the process where plants take nitrogen from the atmosphere and convert it to a form plants can use.
“What sets Dr. Purcell apart from other crop physiologists is that he understands the importance of the baseline genetic components of a cultivar that impact its metabolism and phenology, which can inform a breeder how it effects plant growth, yield potential and stress response,” said Trent Roberts, interim department head and professor of soil fertility and soil testing for the crop, soil and environmental sciences department. “Most crop physiologists are not doing that.”
Purcell credits his interest in blending physiology with genetics to his advisors for his master’s degree from the University of Georgia, Doyle Ashley and Roger Boerma. Purcell said that their groundbreaking research in genetic differences in photosynthesis in soybean and the relationship of photosynthesis with grain yield were an inspiration for his research.
Early in his career, Purcell turned his attention to light interception, a key factor affecting canopy photosynthesis. He developed methods using then-new digital cameras in the mid-90s to streamline the process of taking light interception measurements. This method is now the standard method and is an early example of high-throughput phenotyping, a big buzzword today.
“From a crop growth perspective, light interception is one of the most important parameters you can measure,” Purcell said. “This little digital image method was really easy to do, where you could take literally thousands of images a day, and it wasn’t sensitive to the instant light level, or the time of day.”
The previous established method using a light meter required the sun to be directly overhead with cloudless skies, severely limiting the number of measurements that could be taken during a day.
The Four Cs
Creativity is a benchmark attribute for what it takes to be a great scientist, Roberts said in his remarks about Purcell receiving the award on Sept. 4.
Three other “C” words that make a great scientist, Roberts said in his speech, are curiosity, communication and collaboration.
“Curiosity about the world around you and knowing how things work only get you so far,” Roberts said. “Creativity, developing novel research ideas and ways to implement those ideas, take you to the next level, and Dr. Purcell is not only curious but also very creative.”
Some examples Roberts gave for Purcell’s curiosity and creativity were using remote sensing measurements for irrigation and photographs to correlate nitrogen sufficiency in crops. Many years before the Federal Aviation Administration created its Part 107 drone pilot’s license, Purcell got an octocopter with Arkansas Soybean Promotion Board support to take infrared and color images of soybean crops. In 2011, the day a story came out about his experiment in Delta Farm Press, Purcell got a cease-and-desist letter from the FAA because it was outside the scope of “recreational use.” He improvised and took to the sky with a kite and balloon instead.
“We knew this technology was going to be taking off,” Purcell said of drones. “We knew that it was going to have a huge impact on agriculture, and we wanted to get some of the methodology down and show how it could be used. I learned more about flying kites than probably any agronomist in the country.”
Roberts said Purcell’s ability to effectively communicate with a wide range of people, collaborate with other researchers, and not just team build but “build a feeling of community,” were also instrumental in his success.
Turning his wheels
Before becoming widely known as a kite-flying agronomist, Purcell could be found bicycling across the country with his wife, Becky. In 1981, after he graduated from the University of Georgia, they joined a couple of friends in a trek across the country from California to South Carolina.
These days, Purcell can still be found biking around the countryside or working part-time as a bicycle mechanic at Gearhead Outfitters in Jonesboro. While he admits it’s a good way to stay fit, he said biking has always offered him space to clear his head. On his bike, he might have even come up with some of his novel research ideas.
To learn more about the Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website. Follow us on X at @ArkAgResearch, subscribe to the Food, Farms and Forests podcast and sign up for our monthly newsletter, the Arkansas Agricultural Research Report. To learn more about the Division of Agriculture, visit uada.edu. Follow us on X at @AgInArk. To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit uaex.uada.edu.
