Drones are being used by a Magherafelt-based company to carry out agricultural contracting work on local farms.

At a farm walk in Limavady last week, Andrew Clarkin from Agri Drones NI gave a spraying demonstration with an XAG P100 Pro drone.

The drone measures 2.9m wide when the four sets of propeller blades are unfolded and has a 50-litre tank for carrying spray, which allows for a 50kg payload.

Andrew Clarkin from Agri Drones NI.

When spraying, swath width can range from 5m to 10m, depending on the height the drone is flying off the ground.

At last week’s local UFU meeting, Clarkin had the drone set at a height of 4m, and he sprayed two fills of water across a field for demonstration purposes.

However, most of the work was done autonomously, with the drone effectively moving up and down the field by itself.

“It’s like sitting in a tractor with auto-steer, the operator is keeping an eye on things and is only going to intervene if needed,” Clarkin said.

When it was time for a refill, Clarkin flew the drone back to the yard. When he took it back to the field for the second time, it knew exactly where to start spraying again. The drone runs on two batteries, which generally give 10-11 minutes of flight time. Andrew usually takes six batteries to each job, so charging is happening while the drone is flying.

Other features on the drone include a radar function for avoiding obstacles, such as overhead wires, and the ability for variable rate application if the field has prescriptive maps.

Water was sprayed across the field for demonstration purposes.

Sprays

The range of products that Agri Drones NI can currently spray is limited to liquid fertilisers, foliar nutrients and biostimulants. Granular fertilisers and seeds can also be spread.

At present, plant protection products (PPP) cannot be applied with drones in the UK or EU. However, Clarkin suggested relevant legislation will change within the next few years as drones are being widely used for pesticide applications in the likes of the US and Australia.

He pointed out that once drone application becomes permissible, PPP manufacturers will need to update labels, as aerial sprays tend to be more concentrated.

For example, a typical application rate for PPP in boom sprayers is 200 litres/ha, but drones need to operate at closer to 50 litres/ha so that re-fills are kept to a minimum.

The drone measures 2.9m wide when the four sets of propeller blades are unfolded.

Benefit

Clarkin said the main benefit of the technology is to get applications on to wet or steep ground which cannot carry heavy machinery.

He gave the example of a 16-acre field which he had sown out in grass seed for a local farmer a few days earlier.

The farmer had the seed bed ready, but heavy rain fell just before he could get on with a tractor and drill.

It was unlikely that the field would dry out enough before the spring, so there was a big risk of soil erosion over the winter. “The farmer was really glad to get the seed in,” Clarkin said.

Pre-flight

Before a drone can take off for agricultural work, there is a long list of checks that need sorted, so jobs can’t be done at short notice.

This includes operational authorisation from the Civil Aviation Authority, flight planning, site and risk assessments, weather and airspace checks, and equipment inspection.

“As the operator, responsibility sits with us to do things right. Agricultural drones have huge potential, but doing the job properly and legally has to come first,” Clarkin said.