Researchers from the Rothamsted Institute in Hertfordshire have been carrying out trials using drones (unmanned aerial vehicles, or UAVs) to assess what use they could be to the farming industry.

Rothamsted and agricultural research council BBSRC have pointed out that the usefulness of an eye in the sky - especially one that can be equipped with all sorts of analytical equipment - shouldn’t be underestimated. Use of drones is becoming much more widespread in a range of industries; Amazon has said drones could be used to deliver parcels in the near future and top-flight football club Everton is already using drones to train players.

Over the past 18 months, Rothamsted researchers have been running trials with an eight-rotor ‘Octocopter’, which they hope will cut down the long slogs and other footwork researchers have to undertake in monitoring crop trials. Though the fully kitted-out Octocopter model currently carries a prohibitive £24,000 price tag, Andrew Riche and March Castle from Rothamsted believe there is huge potential for the technology, and are using their prototype to monitor crop growth over five hectares at the research Institute.

The Octocopter can be controlled by an operator on the ground, or fly itself using GPS. It can carry 2.5 kg of kit and can fly up to 122 metres above the ground (legally). Though the maximum flight time is only 13 minutes, the machine’s batteries only take one hour to recharge. Different cameras can be used to take conventional images, or to look at soil temperature, which can give indications about possible crop stress. There is also the potential to look at crop biomass, which is exciting the researchers, as this will allow them to compare different crop varieties or systems.

“This year we have focused on monitoring crop height through the season and also crop maturity, said Andrew Riche. “Different wheat lines mature at different rates, and we regularly monitor this on the ground – this year we hope to have done it from the air.”

“We have found that we can measure crop height accurately from the images. We can also measure NDVI from images, usually we take these measurements on the ground, but the octocopter should be much quicker,” Riche added.

Future for Drones: from monitoring to actively farming

Although the maximum flight time of 13 minutes may seem rather short, the Rothamsted team said their machine can, in just 16 minutes flight time, collect an amount of data that would take a researcher four hours to do on foot.

The researchers also believe there is a potential to scout for pests or diseases, especially those that cause discolouration of crops, such as wheat rusts, allowing farmers to better target pesticides or introduce natural predators to a given area.

Though the researchers believe there is clear potential for the technology, Riche doesn’t think fully automated drone agriculture will be taking off anytime soon, especially in the UK, as the octocoper can’t currently fly in the rain. He said, “There are currently companies offering a service to farmers for monitoring fields by UAV, however this is a specialist area at present, as current legislation makes it difficult to operate UAVs over a large area. And I think we are a long way from seeing seeds or pesticides being applied by UAV, however I think they have an important role in monitoring field experiments”.

There are also limitations to the use of drones, relating to air space and privacy of the general public. Riche explained, “As the aircraft is greater than 7kg and we are within controlled airspace by being close to Luton Airport, we have to ring air traffic control each day that we fly to get permission.”

BBSRC has released a video of Riche and Castle piloting the drone: