[petewailes]

It's likely being used in place of a propane set up for heating something like chicken houses, or maybe lambing sheds if it's somewhere cold.

Propane bills generally run about $30-60k for a decent sized operation, whereas if you burn bales (especially in something designed for it), it'll run you about 25-40% of that, depending on the year and price of straw.

It's a cheap source of likely locally available fuel.