NEWS for North Dakotans
Agriculture Communication, North Dakota
State University
7 Morrill Hall, Fargo, ND 58105-5665
August 6, 1998
Transportation, harvest schedules and a variety of alternative crops are conspiring to make crop storage particularly tight this harvest season. That means advance planning is needed to protect harvested crops with temporary storage facilities that protect them from moisture, wind, birds, rodents, and insects, says a North Dakota State University Agricultural Engineer.
"The best option is to store the crop in a building if possible," says Ken Hellevang, an agricultural engineer with the NDSU Extension Service. "Pole barns or machinery sheds can make good storage facilities if they're prepared correctly."
Walls may need to be reinforced with cables or braces. Self-supporting interior walls are another option. Grain exerts a force on a wall of about 23 pounds per foot of grain depth, Hellevang says. That means that when grain is six feet deep, the bottom of the wall has about 138 pounds of pressure per square foot pushing out at the bottom. Building manufacturers can often provide strength information.
Buildings used for grain storage should be well-drained. Cover floors with plastic to prevent moisture from migrating from the soil or through cracks in concrete floors into the grain, Hellevang advises.
"Cooling the grain with aeration is extremely important for proper storage," he notes. "Cool temperatures minimize mold growth, limit moisture migration, and control insects." An aeration airflow rate of about 1/10 to 1/5 cubic feet per minute per bushel is recommended for dry grain.
"If you must pile the grain outside on the ground, drainage is crucial," Hellevang says. "The pile should be on high ground and the earth crowned under the pile. Place plastic on the ground to keep ground moisture from wetting the grain." Plastic may not be needed if the pile is on well-drained gravel-type soil.
Cover piles with plastic or a tarp to reduce wetting by rain and snow and to minimize damage by wind and birds. A smooth surface will aid in drainage. Position and extend the cover so that water is channeled away from the pile.
"Condensation under the plastic may cause severe problems unless it is controlled with aeration," Hellevang says. Air must flow near the plastic to reduce the condensation and carry the moisture away. Cooling the grain with aeration will improve the chances for success. Run the pile north and south to allow the sun to dry off the sloping sides.
Large round bales can be used to form a bin wall, but probably will need to be held in place by cables. With grain piled to five feet against the bales, grain exerts about 115 pounds per square foot against the bottom of the baleenough force to push bales out of place. Plastic along the inside of the bales will help keep grain in and water out. Peak the grain so it flows onto the top of the bales to form a smooth top. The plastic or tarp should drape over the top of the bales, so the water flows to the outside of the bales.
"It's especially important to monitor crops stored in emergency storage frequently for potential problems," Hellevang says. "Market that grain or move it to better storage facilities as soon as possible. You cannot expect grain to remain in good condition if you use temporary storage for long-term storage."
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Source: Ken Hellevang (701) 231-7243
Editor: Tom Jirik (701) 231-9629
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