Dennis’ old crop canola had stored well through the spring and summer of 2011. At the end of August, sensors indicated that the canola in one of the eleven steel bins was heating up. Dennis said he had put the canola in the bin cool and dry, at 9.1 per cent moisture. He asked me to visit his mixed grain and cattle operation north of Manning, Alta., to take samples of the canola in that bin to determine how much it had heated.
The bin, number seven, was heating up. It was warm to the touch, and when I opened the roof vent, I smelled the distinct odour of heating canola. I asked Dennis if he’d ever had trouble with this bin before. “As a matter of fact, I have,” he said. “This is the same bin that barley heated in last year. Both grains were put in the bin dry or overdry. I don’t understand it,” he said.
Because this bin had heated up two years in a row with two different grains stored in it, and records confirmed that Dennis had aerated his bins for 10 days after filling them with canola in November 2010 in order to ensure they were cool enough and to eliminate any pockets of moisture, I concluded the problem must be something to do with the bin itself and not the crop being stored. The bin appeared to be exactly the same as all of the others, with no obvious damage. Not sure what was going on with bin seven, I decided to bring up Dennis’ heating canola problem with my colleagues at our regular Monday morning meeting.
“I’ll bet you five extra loads off next week’s canola allocation that I know what’s causing the trouble,” said one of my colleagues. He asked me to meet him at Dennis’ farm that evening with a bright spotlight.
That day, Dennis completely emptied bin number seven at our request. At nightfall, while Dennis and I waited outside of the bin, my colleague lit the spotlight from within, and directed the bright light around the inside of the bin along the top of its walls. From outside, we saw the light shining through little gaps into the darkness, showing us where the seal between the wall and roof joint had been broken. We climbed up to investigate and we found the foam seal had been picked away by birds! The areas where the seal had been broken were letting moisture in.
Dennis applied some spray foam insulation to these areas, sealing the gaps the birds had created between the wall and roof joint. Since birds do not like spray foam, they did not bother with bin seven again, and the moisture and heating issues did not reoccur.
Checking bins regularly is an important way to reduce storage losses. Moisture and heating issues due to broken seals in your bins can quickly eat away at your profits.
As Dennis and I both learned from this experience, if there is a problem and you believe all other best management practices have been followed, keep looking for the source of the problem, and don’t be afraid to ask the opinions of others — they may have had similar experiences and can offer solutions, advice or guidance. †