Washington State University (WSU) is deploying an eight-rotor unmanned aircraft system (UAS) as part of a long-term study on subsurface irrigation in vineyards.
The researchers are applying water directly to the roots of a vine in the ground, rather than dripping water on the ground near the drunk. Through the Federal Aviation Administration-approved study – an effort to reduce the amount of irrigation water used to grow wine grapes – the team uses an octocopter, capable of carrying up to 9 lbs. of equipment, to measure the temperature of the vine canopy and how the water transferred from the roots to the canopy is being used during various growth stages.
Using footage captured from the camera-equipped UAS, the team can assess the status of plant health known as “canopy vigor” and relate that to irrigation water use and evaporation from grapevines.
“We can do measurements on the ground, but they’re time-consuming and laborious and take a while to process,” explains Lav Khot, assistant professor in the WSU Department of Biological Systems Engineering and
affiliate faculty for the Center for Precision & Automated Agricultural System. “With the small UAS, we can get real-time measurements in minutes with incredible accuracy. It’s a huge advantage.”
In the first year of the study, Khot says, one treatment used 60% of the normal amount of water, and the vines had no yield differences. However, the three-year project is testing a variety of fields to see which levels of subsurface irrigation – and at which intervals – can provide the best outcome for growers.
WSU says the drone flies a few-hundred feet above the vines (within the visual line of sight of the operator), hovers in pre-programmed locations for a defined time period and moves to the next location. Khot stitches together the images to get data for an entire vineyard study plot.
“It’s very early, but it seems subsurface irrigation is working,” he continues. “The berry size is the same as [with] control treatments, but we need more data. We’re really excited about the potential.”