The fire service in Ashburton says a haystack containing more than two-thousand bales, which is on fire, may take several days to burn out.
The Rural Fire Service was called to the fire at 10.30am on Friday at Westerfield, between Ashburton and Methven.
The spokesperson says while the fire is contained, it is letting it burn out.
Seven fire appliances, a tanker and a helicopter were in use at its height.
The fire service will continue to monitor the fire.