Fire crews tackled 100 tonnes of hay ablaze at a large barn near Bridgwater.
Five fire engines were sent to Merlyns Farm, Tuxwell Road, Spaxton, at 4.10pm yesterday.
Crews used three hose reel jets and one compressed air foam jet to get the flames under control, and two farmyard telehandlers were also used to move about 50 bales from the source of the heat to a field where they were damped down.
A thermal imaging camera was used to ensure the blaze was out.
Devon and Somerset Fire and Rescue Service said the cause was accidental.