Pros and cons of using drones in agriculture

Once labelled more as a toy than anything else, drones are now widely used across a massive range of industries including precision agriculture, forestry, horticulture, agribusiness and at universities.

While there are plenty of benefits that come with drone use for precision farming, there are also shortfalls that come with it that might not have occurred to you or been mentioned to you.

So before you simply hop on the bandwagon just because, make sure you weigh up the good and the bad.

Drones allow real time monitoring at a far more accurate and cost effective level than satellite imagery, helping farmers make data-driven decisions.

Onboard sensors, depending on their quality, can capture data for vegetation indices, plant counts, plant height, soil moisture levels, soil temperature, topography/3D mapping, visual/thermal mapping, hyperspectral maps, paddock uniformity, biomass estimates, plant diseases, nutrient and herbicide resistance mapping, amongst others.

Stepping out of the crop-mapping realm, drones are used for aerial photography in livestock operations, small-scale aerial spraying, for drought assessment, tree classification, monitoring watering points, pest animal management, aerial survey for irrigation design and insurance loss documentation.

Australian UAV regional manager for Wagga Wagga, Lachlan Feeney, said drones do not replace satellite data but are ideal for high value crops or high resolution spatial data.

Drone data, when weighed up against a cost-benefit analysis, can help farms become more efficient, manage variability within a farm, and hopefully save the farm money in the long-term.

Having said all that, however, do watch out for expensive software updates and data processing fees that might really sting. We will get to that later.

This is only if you are flying on your own property and not flying for commercial purposes, and you are operating a drone that weighs 25kg and under.

However, if your drone or aircraft weighs between 25kg to 150kg, you will need to obtain a remote pilot license.

If you are a commercial operator (who is getting paid to fly the drone), you might need to obtain a license by CASA, unless the drone you are operating weighs less than 2kg.

While you might not need a license, it doesn’t mean you can start your drone up whenever you want. You will still need to apply for what is known as an aviation reference number from the Civil Aviation Safety Authority (CASA), and notify them when you intend to fly and where. However, once you sent the notification to CASA, it is valid for two years unless you change drones or wish to operate from a different place in which case you will need to submit a new notification form.

Although it might not be a legal requirement for you to obtain a license to operate these drones, experts strongly recommend some form of training at the very least to equip yourself with some basic knowledge on drone flying.

“It's really important that you get at least basic training on how to use the drone safely, how to have situational awareness and how to manage the batteries and electrical systems of the drone,” said Dr Joel Spencer from the Institute of Drone Technology.

“We’ve seen now more and more organisations, even though they're flying drones that weigh less than 2kg, electing that everyone should do a remote pilot license because it's about community and stakeholder engagement and showing that you're an organisation that takes its safety obligations seriously.”

Farmers who wish to train themselves or their employees on operating drones should look for CASA accredited training providers like the Institute of Drone Technology to obtain their accreditation.

Regulations for non-commercial drones could be found on the Civil Aviation Safety Authority website under REPL or RPA (remotely piloted aircraft).

On the topic of safety, drones are used a lot in applications where it is too difficult or dangerous for humans and big machines to attempt.

If you have land with steep slopes for example, imagine how dangerous it would be to carry out tasks such as spraying over those terrain.

For this reason and more, DJI has developed its Agras MG-1 drone specifically for agricultural spraying use. It can carry up to 10kg of liquid in its tank and can cover an area of up to 6000 square meters in just 10 minutes.

If you need to do some land surveying to check on your infrastructure but certain areas of the land are inaccessible by car, a drone can take on the job easily and do it faster than you could using a car or farm vehicle.

According to Australian UAV’s Lachlan Feeney, having more precise data may lead to more sustainable farming practices.

“We are looking at more unpredictable times with respect to weather – the Riverina’s climatic forecast is for more intensified summer thunderstorms and overall lower rain throughout – so we are moving into climate predictions that are harder to grow crops in,” he said.

“Growers are marrying technology with the uncertainties of the future.

“It’s giving people another arrow to the quiver to make the solutions on the farm and they need to consider if the cost is worth it."

Data ownership has always been a big question mark when it comes to precision agriculture, but in this case, client owns the data.

Which means any maps, images, footage or crop data you obtained with your own drone belongs to you.

This wasn’t the case a while ago but with drones using more app based software, it is now easier than ever to grasp the art of flying drones.

Feeney was previously a technician in the Australian Defence Force, working on Black Hawk helicopters, but conceded learning to use the drone technology was challenging.

“As we move away from using remote controls and laptops to get precision ag machines flying, and go to app based software, it will be easier and more accessible without having to invest so much time into piloting and learning to use the equipment,” he said.

It goes without saying that when the weather is terrible and there are massive gusts of wind, there is no point flying an aircraft as for one, it won’t fly properly, and two, it won’t be able to collect accurate data or imagery.

Some drones are more stable than others, so if you experience plenty of windy conditions where you are, make sure you pick the right one for your needs.

When it comes to weather conditions for flying, consider low wind speed for craft stability and as little scattered or broken cloud as possible to prevent shadows on crop imagery.

Those who live in regional Australia are no strangers to poor Internet connectivity, and in most cases, flying a drone will require some connectivity.

For example, drone software often use Google Maps as their base layer so will therefore require the Internet to work properly, so the lack of connectivity in remote areas can be a problem for this reason.

Australian UAV’s Lachlan Feeney suggests planning the night before, or ensure there is 4G coverage in the paddock before you fly.

Birds are perhaps one of the most prominent problems you will face when operating a drone out in the open as birds will mistake your gadget for prey and shred it to pieces if you’re not careful.

Within minutes of launching a multi-rotor drone for a farmmachinerysales.com.au demonstration flight, two wedge-tail eagles appeared from nowhere and began stalking the aircraft.

According to Feeney, valuable mapping time could be lost by pilots trying to out manoeuvre eagles in the field during data collection.

He said an eagle’s sharp talons were easily able to shred expensive air craft.

“When flying fixed wing drones, eagles have a propensity to attack,’’ he said.

“The wedge tails have a stalking behaviour where they sit behind, above or off to the side of the drone, and they will match what the drone is doing, looking for an opportunity to ambush what they believe is prey.

“So if you are flying big mapping runs in rural areas, the cost of losing a drone to eagle attack needs to be factored in.”

Flying a drone for fun is, well, fun; but if you’re flying it for work, it’s a different story altogether.

There is little romance with flying a drone as operators have to be prepared to stare at the sky for hours, putting up with a stiff neck and sunburn.

So make sure you slip slop slap before standing out in the sun, or fly the drone when the sun is not at full bore.

As aforementioned, drones are a cost effective way of collecting data compared to satellite imagery, but the software and hardware that accompany them could be expensive.

The senseFly eBee agricultural drone gives you the option to buy the rights to have data processed, but is rather expensive.

“Each software licence can be multiple times more than the drone and growers can buy that licence for their farm, and in 10 years time it may need updating,” Feeney said.

One of the limitations in the growth of drone technology in precision ag has been in the speed of data delivery, which could take up to a week, according to Feeney.

“If that doesn’t tie in with the time a grower needs to get on to that crop with fertiliser or pesticide, there can be a loss in time that makes flying the drones useless,” he said.

“Sony is developing a camera to capture real-time NDVI which means growers will be able to assess on the day but the precision of this equipment may be rudimentary compared to some higher quality sensors available.

“Essentially, trading precision for speed which certainly has its merits for broader-scale sweeping statements about an area.”