LSU graduate student Anna Coker has been working with drones, also called unmanned aerial vehicles, or UAVs, to analyze plots of various rice varieties to determine midseason nitrogen needs.
Coker’s work earned her a master’s degree in that area of concentration, and she is now pursuing a doctorate.
Her study will focus on comparing data obtained from a land-based GreenSeeker sensor and an airborne remote sensor on a UAV that measures near-infrared light to obtain a normalized difference vegetative index that can be used to gauge plant growth stages and plant health.
Dustin Harrell, LSU AgCenter rice extension specialist, said the Greenseeker device provides sufficient data for a nitrogen prescription. But he said the GreenSeeker can only be used for a small portion of a field because it is handheld, and it is too heavy to be attached to a drone. A drone equipped with a sensor can fly over an entire field.
Using data collected from fields in 2017 and 2018, she has determined that a new algorithm based solely on a UAV-derived normalized difference vegetative index should be developed to interpret more reliable data from the UAV.
“I’m looking at the relations between the GreenSeeker and the UAV,” she said. “We’re also trying to determine ways to eliminate the errors you’ll get with a UAV.”
Those errors occur because of natural variations in the UAV’s passive light sensor caused by clouds and the position of the sun at different times of the day that affect the normalized difference vegetative index readings, she said.
Coker has a solid agricultural background, and she has farmed rice with her father in Arkansas.
“This past spring, I had time to help with the tillage, so I drove a tractor,” she said, “and during the summer I helped with the poly pipe and shoveled levee gates.”
The LSU AgCenter and the LSU College of Agriculture