Drones are being used for an ever widening range of agricultural applications enabled by new technology and diminishing regulatory constraints. Most current drone options are small, battery powered units and when equipped with cameras or other sensors they are very well suited to scouting and monitoring tasks (see this earlier article). There are a variety of other farm-related tasks carried out with ground-based crews and equipment. Which of those are amenable to a drone-based solution? There is also a well-developed agricultural aviation industry based on piloted aircraft. Could some of those activities be handled by drones? To explore these questions, I interviewed two high capacity drone manufacturers and two ag aviation companies.
An entrepreneur named Bentzion Levison grew up in the US and moved to Israel when he was 10. He ended up serving there in the military, and then five years ago he decided to start a business called HevenDrones to pursue a vision of drones as “actionable, flying robots.” Doing that would require drones that could carry a significant payload and have a longer operation window. HevenDrones’ first iteration was a battery-powered version that could carry 75 pounds, but it only had a 20-30 minute operating time between charges. Levison decided to try a hydrogen powered unit. Such engines were commercially available, but they had to be optimized for this application. After some development his company came up with a drone design that can carry a 75-pound payload for 2 to 3 hours. It has both a hover-mode and a fast-flight mode so that it can do detailed tasks but also cover substantial distances. Compressed hydrogen is available in tanks, but HevenDrones has also developed an in-the-field electrolizer that can use power from the grid or a solar panel to generate hydrogen from water and compress it. The drones can be run by an operator or by a computer. They can also work as a “swarm”. The drones are designed to fit in the back of a normal pickup truck.
HevenDrones is pursuing many applications for this high payload drone including homeland security, early interventions in firefighting, installation and upkeep of solar farms, emergency delivery of food and/or medical equipment, delivery of COVID tests, construction and mining. They are also interested in pursuing agricultural opportunities and started with a project doing pollination of palm trees in the UAE
There are other manufacturers of higher payload drones. One of these is a Texas-based company called Hylio founded by Arthur Erickson in 2015. Erickson grew up in a farming region but started his career in aerospace engineering and only later got involved in agriculture. Hylio sells several categories of drones including one that can carry up to 18 gallons of liquid or as much as 180 pounds of other material. They began selling these drones in 2019 and now have 500 of these in the field. They are battery powered and are typically landed for charging and payload replacement every 10-15 minutes. They provide contract services and also supply equipment to “gig operators.” Their technology has found some unique uses such as patented “clam seeding” method for placing baby clams in ideal “nesting” areas along the coast. Another use case is with the Canadian company Flash Forest who uses their drones for reseeding efforts, especially after fires.
A major focus of Hylio’s large drone service involves applying fertilizers, spraying crop protection products, and spreading cover crop seeds, roles that have typically been fulfilled by the existing Agricultural Aviation sector using piloted, fixed-wing and rotary aircraft. HevenDrones is also pursuing those opportunities.
There are several advantages of aerial application that apply to both piloted and drone-based options. These options are possible at times when the soil is too wet to drive a tractor or when doing so would be difficult because of the density of the standing crop. Aerial applications can be very efficient in cases where only part of a field needs to be treated because of soil variation or if an invasive weed, insect or disease has only begun to encroach on the planting. In any case doing work from the sky helps to minimize the soil compaction that comes from wheel traffic. Cover crops are widely recognized as a good idea for overall soil health, for “regenerative farming,” for carbon sequestration and for erosion control. But the adoption of this approach has been limited partly by cost but also because the best time to seed a cover happens to be during a very busy window in terms of a farmer’s other tasks. That happens to be a window that is relatively open for aviators and so that has become a major driver for the practice.
In the realm of aerial applications, the drone and piloted options are more complementary than competitive – each having advantages or limitations depending on scale and logistical complications. An airplane can carry 500 gallons of liquid and apply that at 2 to 5 gallons per acre with precision control of droplet size to minimize drift and the ability to turn the spray on and off as needed for subsections of a field. A drone can fly at a lower altitude above the crop and can target even smaller spots for a spray if that is what is needed – e.g. less than three square meters. For large acreage row crops the payload of even the higher capacity Hylio and HevenDrones would have to be replenished so often that the labor cost of doing so becomes a problem. However, even in the Corn Belt a farmer might have a relatively small block of vegetables or of a seed crop at a scale that is a good fit for a drone. The logistics and economics would also be quite different in high value fruit and vegetable crops.
There are sites with powerlines or trees that are problematic for a fixed-wing airplane to navigate and could thus be better handled with a drone. That logic would apply particularly well for mosquito abatement in riparian zones. A drone might not be an efficient way to spread thousands of pounds of fertilizer or cover crop seeds on large fields, but it would be a great way to set up “strip trials” of different seed mixes for comparison during a research project.
It will be very interesting to see where this technology goes over the next few years. There will likely be more specialized robotic roles such as collection of soil samples, gathering fruit samples to anticipate an ideal harvest timing, and possibly herding of animals. It will also be interesting to see where the hydrogen power alternative will end up having its best fit.