Seven fire appliances were called to yesterday's blaze, which destroyed the 20m by 5m barn and threatened to spread to a nearby building and silo full of urea.
Balclutha Volunteer Fire Brigade station officer Stacey Verheul said it took a lot of people-power to stop the fire being spread by the high winds.
Three crews from the Balclutha brigade were initially called to the fire.
However, when they arrived at the site they requested back-up and two appliances from Clutha Valley and two from Waihola attended.
Back-up was needed to suppress the fire and protect the urea, which was identified as a safety issue, Miss Verheul said.
A digger was also used to help put out the still-smouldering hay and firefighters remained at the site damping down hot spots for most of the day.
There were no vehicles in the barn but it was full of hay, which fuelled the intense fire, she said.
Miss Verheul said she could not comment on the possible cause of the fire.
