High fliers: The increasing use of drones in agriculture
Drones are increasingly being used in the agricultural sector to aide precision farming, Society of Precision Agriculture Australia writes
Farmers, agricultural consultants and researchers have taken a great interest in drones over the past few years and the field continues to be one of the major growth sectors – fuelling the development and release of drone systems tailored specifically to agricultural applications.
The drone itself is simply a platform that offers particular advantages over other overhead imagery and sensing options, such as satellites and manned aircraft. The main advantages of drones are their relatively low cost to own and operate, and their ability to fly under clouds, and as often as required.
Before bringing drone technology into farm management, think about the application, and the platform and accessories.
The biggest questions to answer are: ‘What information do I want the drone to collect?’; and ‘What tasks do I want the drone to perform?’
Most drones currently on the market come with standard cameras capable of capturing still images (digital photographs) and video footage in the visible light range. These drones can collect visually appealing footage for a range of uses such as routine inspections, checking for damage after floods, frosts, or fire events, and real estate. They can also find application in time and motion studies at critical times such as harvest and checking water troughs, fences, irrigation, and livestock.
There are also opportunities to use these standard images to assess germination and determine plant density to assist with decisions such as whether to replant parts or a whole paddock. Crop scouting without entering the paddock can assist with several key decisions that a farmer or agronomist might make based on visual assessments of a crop.
These activities are potentially very informative and time saving, and can overcome constraints such as gaining access to paddocks immediately after rain or other weather events. These images can also be used in a similar manner to hand-held digital cameras to monitor and evaluate trials or seasonal effects on different varieties.
To use a drone to collect data that has additional value in terms of decision making and precision agriculture, the user may need to add other sensors to the drone platform. With the appropriate sensors on board, drones can be used for a wide variety of applications such as:
• Assessment of plant greenness or photosynthetic active
biomass (which might correlate to nitrogen)
• Crop stress (for irrigation or other management)
• Weed stress (for fallow spraying)
• Insect activity (hot spots)
• Crop maturity or ripeness (for harvest or desiccation) • Assessment of soil colour and ground cover
• Yield estimation
• 3D mapping for land levelling or development.
For these applications to be possible the drone platform needs to be fitted with the correct sensors for the task and supported with the appropriate software to analyse the data collected.
There is now an obvious move toward the commercialisation of agricultural drones that include a package of hardware and software specifically tailored to agricultural industries. Early agricultural drone systems have also been brought to market by leading drone manufacturers to undertake a variety of tasks such as aerial spraying and seeding, bird scaring, and water sampling.
Currently, there are four drone platforms commercially available, each with specific properties and uses in agriculture: 1. Multi-rotor
2. Fixed wing
3. Single rotor
4. Fixed wing hybrid.
SENSORS AND SOFTWARE
Flying a drone to make crop, livestock and infrastructure inspections is quite easy and relatively inexpensive.
If you want to use the drone to carry data-collecting sensors to create maps and make management decisions you will need to ensure that you have a drone platform that is physically capable of carrying the necessary equipment, have access to data and image-processing software (either purchasing the software or
subscribing to a service), and have the ability to transfer the maps to a variable-rate applicator.
The software identifies and matches reference points in each photo and ‘stitches’ the images together to produce one seamless image of the area or paddock of interest, viewed from directly overhead.
If a flight takes 20 minutes and the camera is pre-set to take an image every five seconds of flight time, this will result in
240 photos to process. Further analysis of the recorded data may be possible to extract specific information required for decision making.
With agriculture seen as a growth sector for drone technology, there are an increasing number of drone systems coming onto the market that offer a range of applications suited to agricultural management and decision making. Prominent brands currently offering agricultural drone systems include AgEagle, DJI (Agras), and Precision Hawk.
In some situations, it may be more cost-effective to engage the services of a specialist drone service to collect and interpret the data required.
In addition to standard cameras, some platforms can carry one or two payloads and many allow the operator to swap payloads, meaning the platform can potentially carry out a number of different tasks using:
• Multi-spectral sensor for crop monitoring (e.g., normalised
difference vegetation index [NDVI])
• 3D photogrammetry cameras
• Thermal imagery cameras (e.g., insect hot spots)
• Dry material spreader (e.g., pellets, seed, fertiliser)
• Water sampling
• Bird scarer
• Sprayer (liquid pesticide, fertiliser, or herbicide).
When deciding which drone platform to purchase, be sure to research the practicality and costs involved in retrofitting additional sensors. Be clear about what you want to be able to do with the drone now and try to envisage future applications.
Farmers, agricultural consultants and researchers have taken a great interest in drones over the past few years
Early agricultural drone systems have also been brought to market by leading drone manufacturers to undertake a variety of tasks such as aerial spraying and seeding, bird scaring and water sampling Drones can collect visually appealing footage for a range of uses such as routine inspections, checking for damage after floods, frosts or fire events and real estate