It sounds like an almond grower’s magnificent dream: Instead of having people walking orchard blocks to make sure your trees are getting adequate irrigation, you just whip out your phone or tablet and chart a course for your drone.
But if the scientists involved in a new project are correct, this is no dream. When growers wake up in the morning, they can draw up a flight plan and check various orchards — without ever leaving their front porch.
Researchers at California State University, Fresno recently agreed to partner with AeroVironment, a Southern California company specializing in unmanned aircraft systems, to find out how much water stress can be picked up with aerial imagery.
Athanasios Alexandrou, Professor and Chairman of the Industrial Technology Department at Fresno State’s Jordan College of Agriculture, said they are now reviewing the literature to determine what levels of stress they will put on a test orchard, a 35-acre block of ‘Nonpareil,’ ‘Aldrich,’ and ‘Price’ that is located on campus.
Following a predetermined schedule, they will fly the orchard with a drone to collect imagery. At the same time, down on the ground, they will be collecting moisture levels of both the soils and the leaves. They will then correlate the data, concluding how much stress can be determined through the air, Alexandrou says.
“The long-term goal of this kind of project is collecting and analyzing data to investigate if drones can pick up water stress without the need to do soil or leaf sampling at some point in the future,“ he says.
Any research that can enable almond growers to use less water would be welcome. Until the recent welcome winter storms, growers were being targeted by people claiming the crop uses inordinate amounts of water.
It’s not really true that almonds use a lot more water than other crops. University of California Cooperative Extension Farm Advisor David Doll, aka “The Almond Doctor,” notes that virtually all food crops need about one liter of water to produce one calorie. Almond growers, who now farm close to 1 million acres in the state, are just more visible than other farmers.
But it would still behoove the industry to reduce water use. Doing it by relying on aerial imagery would have the further advantage of helping to lessen growers’ reliance on hiring increasingly scarce workers.
“Ultimately we want to help farmers reduce their labor force, to get information from fields without sending out so many employees,” Alexandrou says.
No Boots On The Ground
Mark Dufau, AeroVironment Director of Sales, Commercial Information Solutions, says they will use the imagery taken by the drone and correlate that with the results of the soil moisture probes and pressure bombs to find out when the trees are truly being stressed.
“In the future, we believe you will be able to go ahead and skip an irrigation even if the schedule says you should water today,” he says. “You can create the most efficient watering plan available without hurting yield.”