Soybean Research Goes Airborne

Andrew Broecker '22 works with Lt. Col. Anne Aldering and Dr. Hongbo Zhang on his SURI project.

Lexington, Va., July 10, 2019—For the past several years, Lt. Col. Anne Alerding has been taking cadets into soybean fields with the goal of learning why some fields produce bountiful crops while others perform poorly. This year, though, Alerding’s research has gone airborne, even as she and others stay on the ground.

Thanks to an interdisciplinary project involving the biology department and the computer and information science department, Andrew Broecker ’22 is flying a drone over a 150-acre soybean field near Glasgow in southern Rockbridge County. The images captured by the drone’s three cameras provide insight into how well the plants are growing—in a fraction of the time it used to take Alerding and her cadet assistants to walk through a field and visually inspect the plants.

“The best way to detect branching [of a plant] is to go underneath the plant and stare at the stems, but that takes a lot of time,” said Alerding, associate professor of biology.

Alerding, though, hadn’t really thought about other options for checking on plants until Dr. Hongbo Zhang,  assistant professor of computer and information science, visited the biology department earlier this year and brought several VMI-owned drones along, with the goal of encouraging collaborative projects.

The next step was to recruit a cadet, and when Alerding met Broecker this spring, he joined up eagerly, well aware that drone experience would go well with his goal of commissioning into the Army and serving in the aviation branch. He’s now conducting his summer work with Alerding and Zhang under the auspices of the Summer Undergraduate Research Institute.

Broecker has quickly learned that research often goes slowly and requires a steep learning curve. “Being a biology major, I wasn’t used to computers and the different types of software and uploading and image analysis,” he commented. “The number one thing [I’ve learned] is patience—not everything goes as planned,” Broecker added. “But it’s definitely been a great experience.”

Broecker explained that the drone’s three cameras capture three kinds of images: RGB (red, green, blue), infrared, and near infrared. The RGB camera takes standard aerial photos, while the other two cameras use heat sensors to measure chlorophyll, a green pigment that helps plants absorb light.

“[The cameras] use red light wavelength to reflect the levels of chlorophyll off the plants,” said Broecker. A higher level of chlorophyll, he explained, means a healthier and more productive plant.

“Soybeans … show tremendous variation in the number of branches they produce, and since each branch increases to the total yield of soybeans, we want to figure out how canopy [leaf] conditions affect branching,” said Alerding. “Drone images will increase the accuracy and volume of our measurements and will help us identify the optimal field conditions to promote high-branching soybeans.”

After each trip to the field, Broecker and Zhang upload the images from the drone’s cameras to a computer running a program that analyzes agricultural data. By the end of the summer, the trio of researchers hope to provide farmer Mack Smith with a research report on their findings so he can use their data to inform future plantings.

Alerding noted that using a drone to monitor crops is part of precision agriculture, which is becoming more common at farms nationwide.

“If you are in the know, and working with Extension agents, a farmer could call in a fly-by where a drone would fly over their crops and monitor them,” said Alerding. “But that’s just starting to take over in our state right now, so we’re sort of at the leading edge of this.”

Zhang, whose trip to the biology department with drones in tow began it all, sees this summer’s work as an example of the kind of interdisciplinary collaboration a small school like VMI can easily produce.

“VMI has a culture to encourage interdisciplinary collaboration through different departments,” said Zhang. He added that another cadet, Kevin Andres ’20, is also conducting drone research this summer, and that he and Andrew are flying drones together and comparing notes. Likewise, he and Alerding stay in close touch—and Zhang doesn’t mind getting hot and dusty when he joins Alerding and Broecker for field work.

“Such close collaborations are making this project successful,” Zhang concluded.

- Mary Price



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