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Grain bags need study
Grain bags seem to be an
attractive if fairly new idea on some farms. Yet very little is known about
their impact on grain quality when they’re used for longer than four months,
says Digvir Jayas, University of Manitoba vice president of research in
A pioneer in grain storage
research, Jayas has studied solid structures other than bags for over the past
30 years. He plans to start a three-year program in late 2010 to monitor seed
germination, moisture content, visible molds, free fatty acid values, CO2 and
O2 levels in canola, and wheat stored in full-size grain bags in western
Canada. He predicts there will be a big difference in storage dynamics.
“In a large bin, about 6
inches of the grain is affected by temperature variation. Bag diameter is so
small and the bag is so long, it means a very large amount of grain is going
through that cycle of daily temperature change,” Jayas says. “We don’t know,
but that variation may have an effect on germination, for example.”
If producers follow the
instructions properly, storing dry grain for a short period shouldn’t pose any
problems. But because grain bags originated in Argentina under mild conditions,
using them in harsher climates could pose challenges.
“For us, moisture migration
complicates the issue. I don’t know how the pattern would develop, but some
would be near the surface because of our cooler temperatures,” he says.
One of the new Loftness
grain bag systems arrived in time for the 2009 harvest at Shaun Moran’s
southern Manitoba farm. Moran did save money and time; he also hit a learning
“It was a big crop. The idea
was, we’d get some bins empty, then pick up the bags and move the grain into
permanent storage,” Moran says. “The ones we cleaned up before spring worked
Two Issues Develop
In spring, a few were still
full. Two issues developed. The minor issue was soft, wet soil that delayed
The more serious issue was
that wildlife, probably deer, punctured a few bags. Snow, rain, or both got
inside and couldn’t drain. Below one larger hole, the nearby grain began to
swell and sprout. Along with it came mold, forming the material into a crusty
mass. Due to the new moisture, weight also increased.
The unloading procedure uses
a shielded cross-auger that fits inside the bag, across its base. Normally,
grain flows into the auger, and a roller picks up the plastic, similar to the
way a window shade winds up. But in a bad section near the end of one bag,
crusty molded wheat broke apart into large chunks that blocked the cross auger.
The crew shoveled out some, then watched the bag stretch and tear from excess
weight as they attempted to continue rolling it up. They eventually cut off the
end and got a fresh start.
“Once we got past that spot,
the rest of that bag went smooth. For dry grain, those bags are good,” Moran
Jayas agrees that grain bags
work best for dry grain and says, for now, they should only be used for
Jayas also says grain bags
should be monitored regularly. He recommends keeping a supply of repair tape on
hand to seal small tears.
Digvir Jayas: 204/474-9404
Shaun Moran: 204/274-2271