Agricultural spray drones

In plain language

A spray drone is an unmanned aircraft fitted with a tank, a pump and nozzles. It flies low over a field and sprays the crop, so a farmer can treat land without driving heavy machinery across it. The idea is most attractive for fields that are wet, steep or hard to reach, and for crops that a tractor would damage as it passes.

Spraying from the air is not the same as spraying from the ground. Wind can carry fine droplets away from the crop, and this is called drift. Published comparisons report that drone sprayers can drift further than ground sprayers, especially when they fly higher or faster.

Rules also differ by country. In the UK, spraying a pesticide by drone counts as aerial spraying and needs a permit. This profile has not confirmed the current US rules for agricultural drones.

Technical explanation

In the United States, drones that spray fall under 14 CFR Part 137, the rules for agricultural aircraft. This profile did not confirm the current FAA notice on how Part 137 drone operators are certified, so no US operator counts or certification steps are stated here.

In the UK, the Civil Aviation Authority regulates the aircraft and the flight, while the Health and Safety Executive regulates pesticide application. Under the Plant Protection Products (Sustainable Use) Regulations 2012, applying a pesticide by drone is treated as aerial spraying and is prohibited unless HSE has granted an Aerial Spraying Permit for that operation. HSE states that there are currently no commercial authorisations for drone pesticide application in the UK, only a limited number of Extrapolated Trials Permits. A January 2023 report says the CAA gave XAG's P40 and V40 spraying drones an operational authorisation, but it does not say that the approval covers pesticides.

The peer-reviewed comparisons are few. A 2025 Scientific Reports study tested spraying drones against tractor-mounted boom sprayers at several forward speeds, and reports lower deposition and more drift for the drones at higher speeds, although the drones gave more uniform droplets. A 2025 Science of the Total Environment study used a tracer to compare a UAV with an electric knapsack sprayer, and reports longer drift distances for the UAV, with drift rising with flight altitude and speed. A 2025 PLOS ONE life-cycle study of wheat in Iran estimated 146.84 MJ/ha of energy for drone spraying and 365.26 MJ/ha for conventional tractor spraying.

What the evidence says

Each statement is typed by the strength of its evidence and linked to the source that supports it.

Limitations and open problems

• Drift is the main concern. The peer-reviewed studies cited here report that drone spray drifts further than ground sprayers, and that drift rises with flight altitude and speed.
• The sources reviewed do not verify how much less active ingredient spray drones use.
• In the UK, no commercial pesticide spraying by drone is authorised. Each operation needs a permit, and HSE grants only a limited number of trial permits.
• The US position is not confirmed in this profile. The FAA notice first reviewed could not be re-checked against the current FAA listing.
• The peer-reviewed evidence is small. The cited studies cover specific crops, sprayers and settings, and one is a life-cycle model rather than a field trial.
• No verified operator or fleet counts are given. Fleet totals outside the US were found only in secondary reports and are not used here.

Possible future uses

Timeline

1. 20 Jan 2023DroneDJ reports a UK CAA operational authorisation for XAG P40 and V40 spraying drones, based on the company's account. Sources: [2]
2. 9 Jun 2025PLOS ONE publishes a life-cycle study comparing drone and tractor spraying on Iranian wheat. Sources: [3]
3. 24 Nov 2025Scientific Reports publishes a performance comparison of spraying drones and boom sprayers. Sources: [4]

Futures this could help bring about

How far away?

Farming with far fewer chemical pesticides

Pilots · 4 of 8 steps done

Glossary

Spray drift

Spray droplets carried by wind or air movement away from the area being treated.

Deposition

The amount of spray that lands on the crop or ground surface it was meant to reach.

Part 137

US federal rules for agricultural aircraft operations, which the FAA applies to agricultural drones.

Aerial Spraying Permit

A UK permit from HSE that is needed before any pesticide is applied from an aircraft or drone.

Sources

1. government report
   Aerial spraying permit arrangements
   Health and Safety Executive, 1 Jul 2026. Accessed 21 Oct 2026.
2. news
   UK approves agricultural drone spraying operations for the first time
   Ishveena Singh. DroneDJ, 20 Jan 2023. Accessed 21 Oct 2026.
3. peer reviewed paper
   Reducing energy and environmental footprint in agriculture: A study on drone spraying vs. conventional methods
   Mojtaba Safaeinejad, Mahmoud Ghasemi-Nejad-Raeini, Morteza Taki. PLOS ONE, 9 Jun 2025. DOI: 10.1371/journal.pone.0323779. Accessed 21 Oct 2026.
4. peer reviewed paper
   Performance evaluation of spraying drones compared to boom sprayers for spray applications
   Safaeinezhad, Ghasemi-Nejad-Raeini, Taki. Scientific Reports, 24 Nov 2025. DOI: 10.1038/s41598-025-25353-1. Accessed 21 Oct 2026.
5. peer reviewed paper
   Pesticide spray drift and risk assessment using unmanned aerial vehicle (UAV) sprayer and traditional electric knapsack sprayer (EKS)
   Science of the Total Environment, 2025. DOI: 10.1016/j.scitotenv.2025.180866. Accessed 21 Oct 2026.

Revision history

3 changes since this profile was created.