By Alberta Agriculture and Rural Development
An Alberta Agriculture and Rural Development specialist says proper storage techniques are a must to maintain the quality of stored grain.
Producers typically manage grain by hauling directly to a grain buyer or putting the product into storage on the farm. If cereal grain is stored on the farm it is important to maintain the quality of the grain.
"The temperature and moisture content of the grain are two important factors that influence the length of time grain can be stored without a change in quality," says Mark Cutts, crop specialist, Alberta Agriculture and Rural Development. "In general, as grain temperature and moisture content increase, the allowable storage time decreases."
For example, grain stored at 18 per cent moisture and 18C can be stored for 20 to 30 days, while grain stored at 15 per cent moisture and 15C can be stored 160 to 240 days before spoilage becomes a concern.
For long-term safe storage (more than 240 days), grain entering the bin at 14 per cent moisture needs to be cooler than 13C. "There may be pockets of higher moisture grain present within a bin that is testing an average of 13 per cent," says Cutts. "These pockets of higher moisture can be a source of spoilage at isolated areas within a bin.
"Grain intended for long-term storage with a higher than desired moisture content should be put through a grain dryer," says Cutts. "Aeration can then be used to keep the dry grain cool and to ensure a uniform grain temperature throughout the bin."
If drying or aeration are not options, the grain should be monitored for heating. Permanent temperature sensing cables can be installed and used to evaluate temperatures throughout the bin. Another option is inserting a metal rod into the bin, leaving it for approximately 30 minutes, then removing the rod and checking it for warmth. "Another condition that must be carefully monitored in stored grain is the presence of stored grain insects," says Cutts. "Under the Canada Grains Act there is zero tolerance for the presence of live insects that feed on grain. As such, checking for the presence of insects is critical to maintaining crop quality. Warm, moist and weedy crops are particularly susceptible and should be closely monitored."
A monitoring program for insects should include checking bins on a weekly basis during the early stages of storage. Visible insects or feeding damage are signs of an infestation. Visual observations, however, are not always guaranteed to detect an infestation. The use of probe traps, which are placed into the bulk grain to capture the insects as they move through the grain, have proven to be an effective tool for detecting stored grain insects.
"In summary, cereal grains that are stored dry and cool (less than 15C) will minimize risks associated with grain spoilage and insect infestations," adds Cutts. "If a crop has the potential to be at risk, regular monitoring of the stored grain is critical to ensure the grain quality is not affected."