One crew from Buckingham, one crew from Aylesbury, one crew from Amersham, a water carrier from Princes Risborough and three officers attended a fire involving a baler and a large area of crops alight.
Firefighters used four hose reel jets, beaters and a water carrier to contain and extinguish the fire.
A telehandler was also used to assist crews during firefighting operations.
Approximately three acres of straw, stubble and bales were destroyed by the fire, along with the baler.
Firefighters carried out extensive damping down operations to eliminate hotspots.