Some 70 tonnes of woodchip and wood shavings have been destroyed by fire.
Wiltshire Fire and Rescue Service was called to the premises just after 5am on Tuesday morning, where fire had broken out in a woodchip dryer housed in a single-storey building at Larkhill, near Salisbury.
Crews from Salisbury, Ludgershall and Amesbury initially attended, supported by a water carrier from Wilton and an incident command vehicle from Devizes.
It took hours to fully extinguish the blaze because of the amount of woodchip involved.
By early afternoon, the service’s attendance had been reduced to just one fire engine, with a crew from Wilton using drags and one hose reel jet to damp down and deal with hotspots.
The site was inspected later, the cause of the fire is as yet unknown and an investigation is underway.