Pioneering the use of drones for precision agriculture

Sunday, October 5, 2014

The use of unmanned aerial vehicles for field management is still limited. But some Ontarians see it as the wave of the future and are pressing ahead with experimental models and specialized cameras to collect data from farm fields

by DON STONEMAN

Trevor Crowe, based in Picton in Prince Edward County, shoots commercial videos promoting products of companies like Bombardier and economic development videos for counties in eastern Ontario. Now he is aiming to use his technical knowledge to boost the farm where he grew up.

Precision agriculture is seen as the wave of the future, and last spring Trevor helped his father, Lloyd Crowe, set up Reynolds Farms Ltd. for precision agriculture by geo-mapping fields from the air as well as the ground. They did so by fine-tuning the GPS-equipped monitors in the cabs of all equipment, and also by flying unmanned aerial vehicles (UAVs) to take high-resolution images, complete with geo-location, and divide fields into management zones that will maximize the benefits of crop inputs.

But, says Crowe, it's early days for precision agriculture in eastern Ontario. Unlike in western Ontario, there are not a lot of companies offering services, so Crowe is doing it himself.

Crowe's "early days" comment might well apply to the use of UAVs in agriculture across Ontario and North America for that matter. The mainstream press calls these flying devices "drones." Transport Canada, which regulates their commercial use, prefers the term UAV. (See "Regulations governing  UAVs not to be taken lightly", page 26.)  

The amount of agricultural work done in Canada with UAVs is a matter of speculation. Transport Canada requires that individuals wanting to fly UAVs for non-recreational use, even on their own farms, apply for a Special Flight Operations Certificate (SFOC). But flights are made for many different purposes, including surveying, mining and insurance claims, and Transport Canada can't readily provide statistics on the number of SFOCs issued specifically for agriculture.

Across the country, there were 155 SFOCs issued for all commercial purposes in 2011, 347 in 2012, and 945 in 2013. According to Transport Canada, "each SFOC contains conditions specific to the proposed operation. Initially, an operator is granted permission to operate over a specific area on a specific date. Once the department is confident in the operator's ability to operate safely, the permission may be expanded."

Still, interest in UAVs for agriculture in particular is growing across North America. According to U.S. newspaper reports, the Federal Aviation Administration opened a drone testing centre in North Dakota in May, the first of six such testing centres planned across the United States. Regulation is tougher in the United States than in Canada.

In June, the New Brunswick government, which doesn't mind calling these devices "drones," announced a $5 million boost to the world's largest French fry maker, McCain Foods Ltd. in Florenceville, and Resson Aerospace of Fredericton, to develop technology, incuding drones, to bolster precision agriculture and help grow potatoes with less spraying.

Though there are a handful of agronomists in western Ontario working with UAVs in precision agriculture, no one is doing this in eastern Ontario, Trevor Crowe says, so he is doing it himself.

UAVs that can be used on the farm are now available "out of the box," he notes. For US$3,700, a purchaser of a product recently offered by Aerial Media Pros in California receives a drone, batteries and software to take and stitch together farm field images. Crowe says it looks very much like the system he developed himself. "I feel I am on the right track," he says.

Crowe, 33, has a mechanical engineer technologist diploma from Durham College in Oshawa. He worked in the auto industry for six years using high-end, computer-aided design systems, first as a plastic injection mould designer and then as a designer of automobile headlights. After he was laid off when the automobile industry crashed in 2008, Crowe says he and his wife, Rachel, decided to make videos in eastern Ontario promoting economic development. "When I bought the drone last year, I had no idea there would be an interest in agriculture," Crowe says.

Crowe flies two UAVs, one purchased for the video company and another specifically for farm work. The cost of the production company drone, a DJI S800 EVO has plummeted from $80,000 to $12,000 to $2,000 in a couple of years. For farm work, Crowe uses a DJI Phantom, which he describes as "the most popular" device in the ag market. The Phantom costs about $1,000 with camera and accessories extra. There is a remote control for taking control of the unit if there is a need, connecting to an iPad.

The essential difference between Crowe's units and the Ag-Pro package is in the modifications Crowe has made. The Ag-Pro package can be used for visual crop scouting only. An operator would fly the field, spot a problem from the images, and scout on foot. Crowe has gone beyond that by developing Normalized Difference Vegetation Index (NDVI) images taken on the farm with his UAV, which carries a modified GoPro Black Edition camera. An NDVI is a measure of a plant's greenness and photosynthetic activity. By measuring the reflectance of infrared (IR) light from plants, stresses such as drought, lack of fertility, insects, disease, weeds or herbicide damage can be detected days in advance of visual signals. An NDVI can't determine what is responsible for the crop stress.

All visible light can be separated into red, green and blue, Crowe explains. "That is what a camera does to create an image. It is called RGB." Consumer cameras have filters that remove the IR light, the light the human eye can't see. But IR light is necessary to measure NDVI.

GoPros are lightweight digital cameras used to shoot many of the amateur, high-quality sports videos seen on YouTube. They also shoot still photos. Crowe typically sets his GoPro to shoot two frames per second to acquire overlapping images of the field.

Crowe converted a GoPro camera to take NDVI images after reading technical papers published on the website www.publiclab.org. He removed the filter that keeps out IR light, and added another filter which breaks visible light into channels.

In addition to what comes with the camera, some expensive software must be purchased or rented. His NDVI images are not ideal, he warns, because the amount of IR measured varies with bright sunlight or cloud cover. He doesn't know if that is an issue with specialized four-channel cameras. "I would suspect that the (dedicated) four-channel cameras are far less susceptible to changes" in light.

He issues a warning to people about "just buying something out of the box (and) not understanding the basic principles of what they are capturing and taking them into consideration."

Not a toy
Standing in a corn stubble field on a farm near Palmerston, an hour northwest of Guelph, vineyard operator Adam Shemrock watches closely as crop consultant Felix Weber activates a nearly metre-wide device that looks like a large toy airplane with swept-back wings.

A small propeller revs up at the rear of the device, called an eBee, and Weber lofts it into the air with both hands as if helping a fledgling bird to fly. It races off across the field while gaining altitude.

Neither a fledgling nor a toy, the eBee is a sophisticated $30,000 computer-guided device with a 16-megapixel Canon camera in its belly, taking and storing high-resolution images of the topography below on a predetermined flight path and altitude, covering every square inch of a 100-hectare field in 28 minutes. A ground sensor technology helps it to land at the end of the flight.

Weber is mostly a crop consultant, but lately he's been spending more of his time promoting and using UAVs for a variety of uses. Early last spring, Weber helped one of his farmer customers make the difficult decision whether to replant all of a winterkilled wheat field or just part. After viewing high-resolution photos from the eBee, Weber advised the farmer that only a small percentage should be replanted for a substantial cost saving.

Non-ag uses for the device include surveying quarries and helping to make insurance claims after floods or even damage from the tsunami that struck the Philippines last year. In Kurdistan, a UAV helps to "demine" fields after a conflict.

But Precision Ag proponents see far greater potential. "The market will be larger in the agriculture sector than in the surveying sector in the United States when it opens up," predicts a confident Brooks Ryder, sales manager for Switzerland-based senseFly Systems, which makes the eBee and an earlier version UAV called a Swinglet Cam. Spray drift damage can be detected next to a farm field. Aerial photos reveal the location of old tile drain runs with Real Time Kinematic (RTK) accuracy.

Shemrock, who is from Adolphustown in Prince Edward County, is looking at starting a business flying UAVs over vineyards. His family runs a modest five-acre vineyard, but he sees potential for UAVs to help other growers with their crops by developing NDVIs.

After extensive research, Shemrock says the investment possibilities range from "a consumer-grade model and you make your own system" costing a couple of thousand dollars, to as high as $100,000, with maintenance and training added in, for The Scout, which is made and sold by high-profile Aeryon Labs Inc. in Waterloo.

Shemrock calls the Scout "a Cadillac. It will do everything you need it to do, but do you need a Cadillac to get some imagery to figure out what to do with your crop? There's a lot to choose from," he says. Shemrock plans to spend $10,000 to 12,000, and see what he can do with the imaging he gets.

Shaun Coghlan, Aeryon's senior product manager, says the Waterloo company's product is well established in military and public safety industries, has commercial applications such as surveying for forestry and is just now making a foray into agriculture.  Devices start at $60,000. A device purchased by Hensall District Co-op for ag use is actually an older model now, Coghlan says. It carries a five megapixel camera. The newest Aeryon UAV carries a 15-megapixel camera which produces images with a much higher resolution.

In July, Shemrock favoured a four-propeller helicopter made by Draganfly Innovations in Saskatoon. He hopes eventually to be able to hire out a commercial product to other growers.

Because he has a commercial pilot's license, Shemrock thinks it will be easier for him to get credentials to fly a UAV in Canada than in the United States, where use has been sharply restricted.

‘Buzz' about drones
According to Steve Redmond, precision agriculture specialist at Hensall District Co-op, there is "a lot of buzz" about UAVs, with companies lining up to make money from them and the technologies involved. "Everybody is collecting data and figuring out how they can make this pay off for farmers."

Redmond, who along with Weber is a member of an agriculture UAV working group with Transport Canada, sees the potential for UAVs, but says the technology may be ahead of the agronomics.

 "There are all kinds of people developing multi-spectral cameras," he says, which are expected to be the next wave of technology that will drive UAV use. Scientists believe that a specific stress in a crop leaves its own signature. They are developing multi-spectral cameras and filters able to identify every pest, whether it is a weed or an insect in field crops, by an image taken by a UAV. When that technology is developed, it will allow an applicator to target a pesticide to specific areas of a field where it is necessary. "That is the Holy Grail," Redmond says.

Redmond started flying over crops with a Swinglet Cam, eBee's predecessor. Last year, Hensall Co-op hired Redmond and bought an Aeryon Scout. The device start at $60,000 and the price goes up with add-ons. Redmond says it is exactly what he wanted. It operates well in the wind. There is no controller and the Scout flies a pre-determined circuit, returning to exactly where it was launched. On top of that, it is built by a Canadian company and "service is great."  Like Weber, Redmond has been helping farmers to locate and geo-reference tile drain runs when they are visible before planting. "It gives you a very accurate map of where existing tiles are. It saves you money when you are splitting those tiles."

Redmond says it has also been a good year to use the UAV and conventional cameras to locate compact-prone areas of less productive heavy clay soils since a late spring forced many farmers to seed fields when conditions were less than ideal. Redmond predicts that, with variable rate seeders, those less productive areas would be seeded at a reduced rate to cut costs, and higher seeding rates will be applied to the most potentially productive areas in a field.

But that is in the future. Redmond acknowledges that farmers are reluctant to spend money on field mapping that may not pay off for three years.

Based in Blenheim, agronomy manager Mike Wilson flies Thompsons Limited's Aeryon Scout over a wide variety of crops, ranging from winter wheat to high-value tomatoes. Wilson says the UAV provides perhaps 150 images from a 50-acre field. The software "stitches them together" for one solid image of the field that can be analyzed.

The biggest feature for selling Thompsons' services now is creating management areas in fields, areas of high versus low productivity. An NDVI image will not provide yield data, but it will direct crop scouts to areas where yield is lower or higher and they can "ground truth" or verify what is seen in the images. Soil sampling will help an agronomist decide if fertility is an issue, or perhaps it is a droughty area, and applications will be changed accordingly to make the field most profitable. "It allows you to manage that field in ways that were not possible before," Wilson says.

In the past, Thompsons has used a camera mounted on the wing of a Cessna flying over fields at 6,000 to 8,000 feet. "If you can do enough acres in a day, this (the Cessna) can be cheaper." And there are some other advantages. "There is no crowd watching (the Cessna). Your neighbours aren't concerned about what is going on. It isn't affecting anyone."

Wilson sees UAVs as "an equalizer" for farms of all sizes, enabling a smaller customer who doesn't have a yield monitor in his combine to see the variability in fields "and allowing him to partake in the services that a larger customer can who is able to collect data."

He sees the potential in multi-spectral cameras. "The bigger challenge will be learning what the images are telling us. That will be where the future is." But he admits that multi-spectrum camera imaging "takes us down a whole different road of complexity."

Back at Picton, Trevor Crowe is using Reynolds Farms as a testing point, looking perhaps towards creating a business flying over other farms, while keeping a sharp eye on the rapidly evolving technology.

"A lot of things have to happen before we get to variable rate seeding," he says. The next step for 2015 might be planting different varieties in low spots at the back of the farm. Some fields need lime, but only in certain places. The drone will show the 10 to 15 per cent of the field where the 2014 crop yield was limited and liming is required. So it won't be applied across the field.

"It's those types of cost savings where drones will find their place." Crowe pauses. "I don't think they have found their place quite yet." BF

Key to precision ag is setting up management zones
Setting up for precision agriculture on Reynolds Farms started in earnest last spring, Trevor Crowe says.

He began creating boundaries of the fields in the software – "one of the most fundamental things you can do" – using Ag Leader SMS Basic software. Then he set up the monitors in machinery cabs so that they were recording cropping information to their full potential, something that hadn't been done before.

Trevor installed cards in the sprayer so that all spray data is recorded. He fine-tuned the Case IH combine monitors recording and mapping yields in the wheat fields, a first step before the more critical soybean and corn harvests. He also installed a variety tracker in the combines, so that the operator "will know at a glance" what was planted and what it is yielding.

Reynolds Farms is a seed dealership and has corn and soybean test plots with split nitrogen applications and different seeding populations. "When it comes to harvest time, the farm is always in such a rush," Crowe says. "It's a joy being able to contribute that to the farm and be able to see it thrive and grow," he says with pride.

The SMS software is vital. Putting all of the maps together later is a major cropping decision aid, allowing yield, variety and fertilizer at tasseling to be overlaid. "We can take that information and apply it to next year."

This year, a new piece of spring tillage equipment was used diagonally across a field. If it was useful in improving yields, that should be revealed on a map after harvest.

Key to precision agriculture is development of management zones, parts of fields with different soil or drainage characteristics, so that these areas can be treated in different ways. Crowe says that Reynolds Farms isn't ready for variable rate seeding or nitrogen applications just yet. But the next step for 2015 might be planting different varieties at the back of a farm where the fields are lower. Crowe notes that the topsoil in Prince Edward County is very shallow. One of the features of mapping is that elevation is also taken into account, including knolls and wet holes.

In mid-August, Crowe was flying fields where low pH might have led to failure of Converge weed controls and where the corn was short and a different colour. He predicts that the drone will show the 10 to 15 per cent of the field where lime is required. "It's those types of cost savings where drones will find their place," he says, adding, "I don't think they have found their role quite yet."

Crowe is pleased that he is able to make a contribution because of the knowledge of technology that he grew up with. "The younger generation is finding its place where farming is traditionally an older demographic. It is becoming the family farm again." BF

Hensall Co-op's GreenSeeker
Using UAVs isn't the only way that the need for nitrogen applications can be determined, Hensall Co-op's precision agriculture specialist Steve Redmond says. This year, the co-op began offering variable-rate nitrogen applications in growing corn via a GreenSeeker-equipped John Deere ground sprayer.

GreenSeeker sensors are located on a sprayer boom three to four feet above the corn canopy. "They are reading the vigour of the corn" and adjusting the nitrogen rate "in real time," says Redmond. At the same time as nitrogen is applied, the GreenSeeker develops maps that show where the crop was growing best in fields already, and farmers will be able to use those maps for future applications, such as variable planting.

The cost is $13 to $20 an acre to go over the fields and apply variable rates of nitrogen depending on the greenness of the crop. Farmers see variable-rate nitrogen as the "lowest hanging fruit" for using Precision Ag to increase their returns, says Redmond, who finds the results from this technology exciting.

By comparison, Hensall Co-op charges $5 an acre to fly fields with a UAV. But farmers don't see value in developing maps now that won't be used for three years, Redmond says.

After attending a precision agriculture conference in early July in the United States, Redmond concludes that American farmers don't put credence in GreenSeeker; they tend to apply all their fertility in the fall so that spring planting isn't delayed.

Fred Below, professor of plant physiology, crop science, University of Illinois, observes that American farmers are worried that "weather constraints" will prevent them from applying an in-season application of nitrogen if it is warranted, but allows that "there is a slow movement toward more side-dressing of N in the United States, due in part to the availability of technologies like the GreenSeeker, but also due to the desire to produce high yields without increasing the amount of fertilizer N applied, and in some cases due to environmental concerns arising from N loss."

Redmond notes that GreenSeeker and UAVs aren't the only way to develop precision farming. Satellite imagery of farms is also getting better and that is another alternative to using UAVs.

With nitrogen applications finished at the end of July for Hensall District Co-op, Redmond expected to be flying the UAV more. "We are still learning," Redmond says. BF

Regulations governing UAVs not to be taken lightly
Regulations that could affect use of UAVs for agriculture are a huge concern for agronomists, such as Thompsons Limited agronomist manager Michael Wilson and Hensall District Co-op's Steve Redmond. Both fear that careless, unregulated recreational users of low-cost UAVs will prompt a backlash that might sideswipe legitimate farm users, so they are careful to follow all regulations.

Palmerston's Felix Weber has a certificate to fly his device anywhere in Canada. But, mindful of the regulators, he keeps a binder full of permissions signed by landowners allowing him to fly over their properties. UAVs are not allowed to fly beyond a buffer zone set up inside the property.

Weber, who has a commercial pilot's license, says the penalty for not following the laws governing UAVs in Canada is a $10,000 fine. He says Transport Canada is "very familiar" with the eBee, and its small size (700 grams) is an asset because the potential to damage an aircraft or person is reduced. "It's about building trust with the regulatory authority," he says.

"Nothing in the SFOC issued by Transport Canada relieves the UAV operator from complying with the provisions of any other relevant act, regulation or law from any level of government (e.g. Criminal Code of Canada, Trespass Act, Privacy Act)," says the federal regulator.

Redmond says flying the UAV is more complicated than one might think. He operates with an assistant, who is in charge of making sure the area is safe and that no person or vehicle moves into the area where the device will land, while also keeping an eye on the sky. The UAV is supposed to fly below 400 feet and civilian aircraft are not supposed to fly below 500 feet, but there are "cowboy" pilots out there, he says. This is especially critical when flying within a zone around a rural airport, and there are more rural airports than one might think, he says.

The UAV must stay a certain distance from roads. And if a field on the other side of the concession is to be flown, Transport Canada requires the operator either to ask the municipality to close off the road, or to land the UAV and relaunch in the other field. The latter solution is simpler.

Transport Canada deals with applications on a case-by-case basis, with an individual assessment of the associated risks conducted for each operation before a certificate is issued. BF