Wednesday, November 17, 2010 – This is the month to make sure stored canola is stable heading into winter. As outside temperatures drop below zero and stay there, canola growers want to make sure canola has cooled throughout the bin.
“If you haven’t checked, you may be surprised,” says Jim Bessel, Canola Council of Canada agronomy specialist.
When outside air is colder than stored canola, another moisture cycle begins within the bin. (See the image at the bottom of this article.) The mass on the outside edge of the bin cools first. This colder air migrates down the outside then up through the central core, picking up warmth and moisture along the way. This creates a pocket of humid and warmer air at the top of the central core where spoilage and heating can start.
“A good rule is to move one third of the canola out of a full bin. This disrupts the moisture cycle and helps cool the mass,” Bessel says. This is a good way to reduce the risk of spoilage for all stored canola, but the practice is especially important if canola at the top of the cone does not cool off because of restricted ventilation.
“For a quick test of restricted ventilation, open the lid at the top of the bin and feel if the expelled air is warm on your face,” he says. “If it is, then ventilation is required and movement of canola may be needed in short order”.
For big bins, moving one third of the volume could mean a number of truck loads. While unloading, remember to feel the canola as it comes out of the bin. In the absence of adequate temperature sensors within the grain mass, this is probably the only effective way to determine if core temperatures are still high in large storage structures.
“Hand probing through doors or roof hatches will likely be unreliable for finding hot spots near the core of the bin,” Bessel says. “If the grain is warm, or if you detect differences in temperature, you may want to turn over the whole bin.”
Aeration in November can help cool the bin, but aeration can be tricky at cold temperatures. Check the aeration fan’s capacity for the amount of CFMs (cubic feet per minute) to ensure the fan capacity is matched to the size of bin. Fans with limited capacity will not be able to move the appropriate amount of cold air throughout the dense mass. This can create a moisture front within the bin, which can create a crust layer. With restricted air movement, spoilage could begin along the moisture front. This crust can also hang up and create a challenge for unloading.
“The canola storage message this time of year is pretty straightforward: Checking bins is the best risk management practice to mitigate major financial losses,” Bessel says. “At $10-$12 per bushel, any loss is like throwing $100 bills into a wood stove.”
For more information, media can contact a Canola Council of Canada agronomy specialist in your region.
This media release is supported regionally by:
Alberta Canola Producers Commission; SaskCanola; Manitoba Canola Growers Association; Canola Council of Canada; Peace River Agriculture Development Fund; B.C. Ministry of Agriculture & Lands.
Published on Wednesday, November 17, 2010