Beachy Head Road in East Dean has closed following a tractor fire at 12.20pm.
15 tonnes of hay were caught alight at the scene.
In a statement, a spokesperson for East Sussex Fire and Rescue said: "We were called at 12.20pm to Beachy Head Road, East Dean to reports of a tractor fire on the main road.
"15 tonnes of hay and a trailer were alight and crews are on scene.
"They are allowing it to burn in a controlled way, with a covering jet of water."
Sussex Police are also said to be in attendance at the scene of the incident.
In a statement, a spokesperson for East Sussex Fire and Rescue said: "We were called at 12.20pm to Beachy Head Road, East Dean to reports of a tractor fire on the main road.