Sky farmers

Crop-spraying drone over crop fieldImage copyrightHylio
Image caption Drones can apply pesticides and fertilisers more accurately, proponents say

Something unusual is happening on farms in the small Central American nation of El Salvador. Many fields, mainly of sugar cane, are now being tended by drones.

Large unmanned hexacopters fitted with 20-litre tanks for carrying fertiliser or pesticides follow pre-mapped routes and spray crops accordingly.

This isn’t a case of new tech replacing old farm equipment – some of these fields are being sprayed for the very first time.

“We’re spraying crops that previously have not being sprayed,” says Nick Nawratil, chief operating officer of Hylio, the firm behind the trial.

“That’s one huge opportunity that drones are opening up.”