Drones can take aerial footage of such high quality that the user looks like a National Geographic videographer. GPS-planted apple orchards look stellar under blue skies. Carrot and onion harvesters appear breathtaking in their capacity to feed the country. But do those images provide any value beyond selling the latest edition of iron?
Kate VanderZaag and her husband Peter have been experimenting with a drone on their 1,800 acres of owned and rented land near Alliston, Ontario. They share an insightful experience.
“We’re open to technology,” says VanderZaag, a fourth-generation potato farmer. “We may not be the first to adopt technology, but we know that we’re on the cusp of change moving towards more information gathering in-season. The drone is not used as a toy. It’s a field tool.”
Two years ago, they purchased a DGI Phantom 3 for $1600 from a well-known chain of camera shops: Henry’s. The high-definition photos are remarkable for clarity. The device can be programmed for a flight pattern of 15 minutes in duration. Son Jonathan has operated the device once a week from emergence in the spring to harvest in the fall.
The drone is not a replacement for field scouting, a job that VanderZaag performs with diligence two or three times a week. She is out taking petiole samples to make sure that the fertilizer program is up to snuff. She’s also looking for weeds, insects and signs that irrigation is working optimally.
“If you’re not collecting data and measuring, then how can you improve?” she asks. “For the last two years, we’ve been tying more pieces of information together – tracking what goes into the bin and correlating that data with the field. It’s not just about quantity but quality too. It’s crystal clear to me that scouting is hugely important.”
All of the VanderZaag potatoes are contracted to chip plants. In one case, there was a load of potatoes with an internal defect of black spots that wasn’t detected until arriving at the plant. Fortunately, the farm’s records can be traced back to the specific bin and compared with aerial imagery of the originating field.
Another benefit of drones is to track seed emergence. A grower cannot spot the patterns up close in the field, but if seed spacing is off, it’s more evident from aerial photographs. Otherwise, this is a problem not possible to see after row closure and impossible to accurately quantify from the ground.
Last year’s potato canopy was so lush with spring rains, that on-the-ground scouting could not identify some problems later in the summer when irrigation was required. The drone identified an area that was suffering from lack of moisture. The problem? A blocked nozzle on an irrigation pivot.
Thanks to the drone, these are the practical problems that could be solved with daily management decisions.
As the first line of defense as a field scout, VanderZaag is contemplating a more synergistic approach with the drone. The question is whether the drone should go up first before field scouting or in the reverse. The next question is how committed can she be to viewing the aerial imagery the same day for remedial action to be taken.
Technology is moving so quickly that droneography may soon be replaced by satellites. Bernie Zebarth is a research scientist, based at the Fredericton Research and Development Centre, operated by Agriculture and Agri-Food Canada. He shared his drone results at the Manitoba Potato Production Days held January 23-25 in Brandon.
“Until last year, we could have obtained a satellite image only every seven to 10 days,” explains Zebarth. “If it was cloudy, then no image could be obtained. Now, one can obtain a satellite image every day, so the odds of getting an image are greatly increased. It is this increased frequency which may be useful in satellites becoming more practical. They do, however, have much lower resolution.”
His research is part of a puzzle that New Brunswick potato growers have been trying to solve. The province’s potato yields have been stagnant from 1980-2015, increasing at 1.4 cwt/acre/year whereas Manitoba’s statistics are 4.4 cwt/acre/year and Alberta’s is 3.9 cwt/acre year.
“Clearly these statistics show we are less competitive, especially given that New Brunswick and Prince Edward Island export so much to the eastern seaboard,” says Zebarth. Tom Dixon, agronomist, McCain Foods has encouraged the use of drones to find out how much variation exists in potato fields. In the 2013 and 2014 growing seasons, the research was beset by technical problems.
“The imagery is complicated,” says Zebarth. “Fifty to 80 images may be taken then must be overlapped. Satellite images are better and, unlike imagery from drones, are already calibrated. However in both cases, there is still the need to develop relationships between the imagery and the crop being measured.”
Flash forward to 2017 and some of those kinks have been solved. There are two general uses, says Zebarth. One is simply to use the imagery to look for things that are different, for example as an aid to scouting. This is one which can currently be done fairly readily using drones. The second is to obtain quantitative data from the images to drive in-season management decisions. For example, one could measure the variation in the crop canopy and use this to drive variable in-season fertilizer application rates. It is this second type of approach we have been trying to do, but are struggling with technical issues.
At Idaho State University, researchers are using a hyperspectral, 100-band camera with a computer-learning algorithm to detect PVY virus in potatoes. To get the kind of resolution necessary to detect PVY, tractor-mounted sensors will work.
In the meantime, Kate VanderZaag is gearing up for the third season with the drone. “We’re building on our knowledge,” she says. “The drone is an integral part of it.”