Doing what the plants tell us
Some countries use three times as much nitrogen as needed to fertilize crops, evidenced in river estuary "dead zones" and groundwater contamination. John Solie's work on agricultural sensors enhances fertilizer application accuracy, reduces waste to benefit the environment, and saves farmers money.
Solie, who holds a 1982 interdisciplinary Ph.D. in Mechanical & Agricultural Engineering from UNL, was born in Wisconsin where his father studied economics and law on the GI Bill. Solie spent summers at his grandparents’ farm in southeast Nebraska. His grandfather, who attended UNL for dairy science studies in the early 1900s, first brought Solie to East Campus when "I was a high school student who liked to build things."
Solie’s family moved to Washington, D.C., where his father worked for the Central Intelligence Agency, and Solie attended the University of Maryland, earning a B.S. degree in agricultural engineering. But Solie became "tired of engineering and then attended Creighton University’s law school while working on the family farm in Brownville."
"I didn’t have the business approach to be a successful farmer, and I didn’t have the personality to be a lawyer," Solie recalled. "But I liked research and campus life and decided to pursue an advanced degree."
Solie likes the idea of his career path as a "bridge" and sees similarity between his pursuits in engineering and law. "Both teach you how to solve problems when you don’t have all the information," Solie said, "with each in its own way helping people to fill gaps and draw conclusions."
"I always walk in two different worlds," Solie said—whether connecting people and processes, academia and acreages, and even (within engineering) mechanical and agricultural disciplines. These varied perspectives helped Solie form a vision and team that has brought success: in his career as a Regents professor with Oklahoma State University and with the innovation resulting from his research group, the Variable Rate Technology
Team. Together they developed the GreenSeeker sensor: a variable rate fertilizer application system that’s now making a difference at farms around the world.
The Greenseeker uses active optical light sensors to look at a growing crop and, by evaluating the amount of light reflected at red and infrared frequencies, assesses the amount of fertilizer optimal for the yield potential of the plant. Like Solie, this device straddles the worlds of engineering and science.
With field testing and refinements throughout the 1990s, the innovation developed into a 60-foot-wide farm implement that applies targeted fertilizer at 15 miles per hour and included 65 onboard computers (a bit "intimidating to average farmers, but the device never had a system failure," Solie said). Recent iterations of the digital version have evolved toward a handheld unit that’s more readily accessible for third world countries—still assessing the plants’ yield potential and applying algorithms that guide fertilizer application—with acceptance in a number of countries including China, Australia, Argentina and Mexico.
Solie said he’s especially proud that Greenseeker use was endorsed by the late Norman Borlaug, the Nobel Prize winner for agriculture who advanced the "green revolution'' for combating world hunger. With this device, Solie has once again spanned perspectives, with a micro-level solution to a macro-based problem.
- Carole Wilbeck