• The use of drone technology is becoming important across a wide range of businesses and industrial sectors, including the Australian agricultural sector.
  • Drones are becoming technically sophisticated, enabling the use of multi-sensor arrays, that can operate either singularly or in unison, to collect a wide range of data for later analysis.
  • Advancements in power storage technology will enable drones to carry more sensors and ancillary equipment while remaining airborne for longer periods of times.
  • WA’s DPIRD is becoming increasing involved in the development of drone technology.

Unmanned aerial vehicles, commonly known as drones, operate without a human pilot aboard. Rather, they fly either autonomously, using onboard computers, or by a ground-based controller, via a system of communications between the two. Drone technology, and their use is rapidly increasing: unmanned vehicles are in use across a range of sectors, including defence, journalism and film photography, express shipping and delivery, thermal sensor drones for search and rescue operations, law enforcement and border control surveillance and weather forecasting.

In agriculture and food production drones are becoming important tools for farmers, land managers and scientists to review and monitor the status of their crops and animals. The Western Australian Department of Primary Industries and Regional Development (DPIRD) is using drones across a range of applications to enhance its effectiveness in helping to manage land use. FDI has taken the opportunity to interview Nick Wright, a DPIRD Research Officer, to discuss the use of drone technology in Australian agriculture.

Interview

FDI – How do you see farmers using drones now and in the future?

Nick Wright – Now

Currently the practical use of drones in agriculture is limited but I believe there is great potential. The limitations revolve around a combination of software, hardware and legal restrictions. Even so, consumer level drones are quite common amongst farmers. At recent agricultural field days in Western Australia, I had the opportunity to talk to farmers about their use of drones, which included checking crops for waterlogging, unobtrusive monitoring of lambing ewes, head counts of sheep while they are in a paddock, and even finding lost sheep in bushland.

There are also a growing number of contractors offering tailored drone services for farmers, including 3D mapping, high-resolution ortho-mosaics and Normalised Difference Vegetation Index (NDVI) mapping, which can deliver data relating to crop health, plant stress and even show frost affected areas. These types of products can be used as inputs into variable rate machinery to optimize processes such as fertiliser distribution. The same drone technology can provide early warnings about crop pests and diseases and can even be applied to identify water leaks in irrigation setups. Currently, most of this technology has limited scope due to the cost and time needed to capture and process the data, especially when outsourcing these tasks to contractors. High quality drones, however, are becoming more affordable and software to review and analyse the data is becoming more user friendly.

Internationally, drones are being used to spray rice crops, replacing manual spraying with increased efficiency. Drones are even being used to plant trees by shooting seeds, that are encased in a nutrient rich pod, into the ground from a low altitude. With one operator commanding six drones, up to 100,000 trees can be planted per day.

Nick Wright – Future

I believe that future automation, combined with computer image recognition, will be the key to getting the most out of drones for agricultural use. Assuming relatively modest advances in technology and some legislative changes, I can see a future where we will have fully automated drone systems. These drones will fly over paddocks capturing data, which will then be processed by a computer to look for weeds or crop damage. This could be carried out on a frequent basis, so you would know very soon if you had a problem that needed to be addressed. In the same vein, this type of system could be used to map summer weeds, which, depending on the scale, could then be sprayed by the farmer or by another drone with a built-in spray system. Drones with the ability to spray are already available – they range in capacity up to 15 litres, providing viability to spot spraying.

A similar system could be used to monitor sheep grazing to check the amount of pasture left in a paddock. It is currently possible to undertake this type of identification and analysis, but it involves quite a bit of manual work. In the future, these systems would need to be fully automated to really be of use to farmers.

The availability of a drone system that requires little human interaction really opens up a lot of opportunities, such as high-resolution time series data sets that farmers could use to monitor plant growth, salinity, waterlogging, erosion, animal movements and much more. In addition, the adoption of improved wireless technology would allow drones to offload high resolution images in near real time. This would enable decisions to be made immediately, which could be followed up with action by, for example, a spot spraying drone or by an alert being sent to a farmer, advising the need for further intervention.

FDI – How will their use benefit farmers?

Nick Wright – I believe drones will offer two fundamental benefits to farmers, including significant savings in time by undertaking menial tasks and gathering a large amount of useful data. The time-savings will come from tasks that can be automated and performed with increasing frequency and potentially greater accuracy, such as monitoring of crops, pasture, stock watering points and more. For instance, currently, fixed winged drone technology is being developed to monitor boundary fences on pastoral stations, which could potentially save days of manual monitoring each year.

With respect to data collection, even ‘consumer’ drones can currently map landscapes in 3D, which could aid farmers in surface water management, erosion monitoring and planning cropping run lines. When additional sensors are added to drones, they become even more capable. For example, adding a multispectral sensor allows the drone to capture data on crop health, vegetation cover and more.

The frequency at which an automated drone system could cover a farm would dramatically reduce the time taken to identify pest infestations, such as areas of canola affected by slugs or wheat effected by fungal disease such as leaf rust. Addressing insect pests as soon as possible is critical to mitigating damage and the availability of quantifiable data can make decision-making easier. For example, if a farmer was able to see exactly how much of their crop was frost-affected, it could affect the amount of grain they are willing to sell prior to production.

FDI – Are there emerging technologies and what impacts might they have on farming?

Nick Wright – Most drones currently being used in agriculture are of the quadcopter variety. These typically get around 30 minutes of flight time, with their lithium polymer batteries, which can be limiting when dealing with farm scale tasks. This limitation is being felt in many industries and therefore a lot of research is being done in this area. The only solution to longer flight times is efficiency, which is possible with fixed-wing drones. These drones have a more traditional plane-like form and once airborne, are significantly more efficient than quadcopters, many with multi-hour flight times. The fixed-wing drones also travel much faster so can cover very large distances. They are limited however, to lighter payloads.

Uses for drones are limited by the types of sensors available. Currently, most drones being used by farmers only have a photographic camera and basic GPS receiver; this alone can be used in a multitude of ways. With additional sensors, such as multispectral, hyperspectral, range finding and mapping (LIDAR), high precision global positioning systems (GPS) and thermal, the potential uses increase dramatically. These additional sensors are available now but for the most part, are only used by researchers and contractors. As prices come down however, and the ease of use increases, adoption rates will follow.

With advances in sensor technology, it has recently become viable to buy third party multi-spectral sensors which can be strapped to the underside of ‘off the shelf’ purchased drones. The data from these sensors can be processed for a multitude of valuable uses. The non-integrated nature of these add-on sensors, however, makes them somewhat cumbersome to use and processing the data can also be unwieldly for the end user. Additional sensors must interface seamlessly with the drone and data processing must be streamlined before they can achieve mass market success.

Another emerging technology that is starting to become available is image recognition, powered by artificial intelligence. Computer programs are emerging that can recognise specific features within a photograph. This technology is currently being used by DPIRD to detect ‘skeleton weed’ in broadacre farms; this technology could also be applied to many other weed varieties or signs of pests within a crop. Further out, I can imagine similar technology being used to analyse livestock for signs of distress.

A prerequisite for the type of technology being adopted is software integration and automation. From what I have seen, few farmers are prepared to spend the time and effort required to get the most out of the current types of drones, due partly to software and legal limitations. For drones to be commonly adopted by farmers, the systems must be completely automated, including scheduled flights, automatic recharging, automatic data offloading and data analysis. Only when this automation occurs will we see large-scale adoption by farmers.

Nick Wright with 3D modelling of soil profile with 3D plastic printer

FDI – What is your department doing to promote the use of drones?

Nick Wright – Most of DPIRD’s work with drones is research-based. This includes 3D mapping of erosion following flood events, the use of thermal sensors to track and count feral pig populations, automated detection of skeleton weed using image recognition, crop monitoring for frost, pests and diseases, and more. For instance, on a trial examining the effectiveness of treatments on water repellent soils, a drone was used to capture data to measure early plant establishment and ground cover, which is strongly linked to crop yield. A drone was used in this instance as manually capturing the required amount of data would have been time consuming and laborious.

Some of DPIRD’s use requires high-end drones with additional sensors, which push the envelope of what is currently possible. Over time, however, these features will become more accessible to farmers as drone and sensor prices drop.

By developing uses and work flows for drones, DPIRD is promoting uptake of the technology and general growth in the drone market. Recently, DPIRD displayed its use of drones at Western Australia’s Mingenew Midwest Expo, Dowerin and Newdegate Machinery Field Days and at the Perth Royal Show. The displays showed farmers what DPIRD is doing in the drone space and gave them an idea of that they could be doing with drones in the future.