World Grain - November 2018 - 88

GRAIN OPERATIONS

Managing stored grain long term
Large harvests, low prices causing storage facilities to hang onto grain longer
by Dirk Maier

door piles can easily exceed 30% to 40%. Typically, soybeans
are not piled on the ground.
MOISTURE CONTENT CONCERNS
Delayed harvest has resulted in higher moisture content than
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moisture content as high as 16% has been reported, which
would be equivalent to storing corn at 19%, and thus may require heated air drying if harvested late in the season. The
maximum recommended drying air temperature for commercial soybeans is 130°F (55°C).
(YHQDWWKDWWHPSHUDWXUHWRRIVNLQVPD\FUDFNHVpecially if the drying air relative humidity is 30% or less. Moldy
and sprouted soybean kernels are an additional concern, which
means moisture content should be reduced by 1 to 2 percentage
points below the recommended safe storage level of 13%.
In the case of corn, some mold-damaged ears and the occurrence of mycotoxins have been reported. Mold-damaged
corn should be dried in high temperature dryers because the
heated air will surface-sterilize the kernels. This will reduce
the chance for mold development during storage as long as
moisture content is reduced by 1 to 2 percentage points below
the recommended safe storage level of 15%.
CORING THE GRAIN MASS
Ideally, corn and soybeans should be screen-cleaned to remove some of the broken kernels and foreign material as
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structure, segregation of smaller particles from whole kernels
occurs based on size and density.
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core and peaked region of the grain mass can take 2 to 4 times
longer than the rest of the grain mass. This increases electricNovember 2018 / World Grain / www.World-Grain.com

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Delayed harvest of corn and soybeans in 2018 across the midwestern U.S. are raising concerns about grain quality and how
well this crop will store long term. With commercial grain
facilities holding a large carryover from the big 2017 crop,
some 2017 carry-over corn and much of the 2018 corn crop
will end up in outdoor piles again. Managing grain in outdoor
piles was the subject of a previous grain operations article
(see World Grain February 2017, pages 78-83). This article
focuses on managing stored corn and soybeans long term in
permanent structures such as bins, silos, tanks and horizontal
sheds where managers have more tools available, including
coring, controlled aeration, temperature and moisture monitoring, and partial unloading.
Ideally, storage structures were cleaned and checked for
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and debris around the facility were removed. For long-term
storage into next summer and possibly beyond, an approved
residual insecticide should have been sprayed on the inside
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about 6 ft (1.80 m) above the foundation, the foundation including cracks and crevices, and the aeration fan inlets and
conveying equipment outlets should be sprayed well in advance of the warm weather storage period to prevent insects
from getting to the grain. Grain protectants are not needed
on cold, dry grain carried into the warmer periods of the year
except perhaps on the grain mass surface.
Low commodity prices and large crops will result in longterm storage of the 2018 crop well into or through 2019. Ideally outdoor piles are picked up before weather turns warm and
humid in April or May. Corn carried in outdoor piles longer
must be closer to 13% moisture content to maintain its shelf
life and minimize damage due to mold spoilage and insect
damage. Damage levels of corn not managed properly in out-

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World Grain - November 2018

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