Most of the grain/oilseeds harvested in Manitoba in 2012 went into the bin very dry, but also very hot (>28C). Good news for not having to dry the grain in fall, but that doesn’t mean you can forget about the potential risk of spoilage. There are reports of grain deliveries in December 2012 being slightly heated, or having some other spoilage issues or insect damage.
As we get colder, a convection cycle starts in the bin, moving the humidity from the cooling grain downward, into the bin centre and then up to the top of the bin. During the process, two things can happen that causes spoilage issues. First, at the top of the bin, moisture can condense and accumulate, creating an ideal zone for spoilage and crusting. Second, grain is an insulator and the ‘bin heart’ that is warm with moist air moving in, can continue to heat, forming ‘hotspots’ of heated grain and/or creating ideal conditions for insects.
To avoid this unpleasant discovery, go check the bins before the New Year. Routine monitoring for symptoms of spoilage (smell, visual signs), checking grain temperature and moisture will help manage the stored grain quality.
- Watch for bins that the snow has melted off.
- Open hatch to check inside. Grain/oilseeds should not smell musty, mouldy or sour and should not have any white or greyish crusting.
- Probe the core of the bin and the probe should penetrate the grain easily. If not, a crust could be forming underneath the top layer of grain or a heated/dense spot may have occurred.
The practise of taking ‘a load’ out of the bottom of the bin and putting it on top or ‘turning’ the bin is also helpful in moving the layers of grain around in the bin and fracturing the heart to reduce pockets of hot and moist grain.
More information on preventing and managing stored grain insects: http://www.gov.mb.ca/agriculture/crops/cropproduction/faa06s00.html
Grain Drying and Storage of Damp Grain: http://www.gov.mb.ca/agriculture/crops/cropproduction/faa05s00.html
Manitoba Listing of Grain Handling, Storage and Process Technology: http://www.gov.mb.ca/trade/globaltrade/oem/english/grain.html