Tips on long-term grain storage
With a record crop and low prices, some farmers will need to store corn beyond July this year. “The 2015 corn crop had excellent quality and should store exceptionally well, if you manage the stored grain properly,” says Kris Kohl, an ISU Extension ag engineer in northwest Iowa.
Kohl offers five tips for storing corn longer than a year.
• Test weight. High test weight indicates good storage properties. Most of the kernels will have a few or no cracks that provide a place for mold to start, with corn testing above 58 pounds per bushel. Fewer fines and drying corn are also associated with high test weight. Grain that dried down in the field will often have higher test weight. When choosing a bin of grain to store over a year, choose the highest test weight, exceeding 58 pounds per bushel.
• Moisture content. Dry grain keeps longer. For corn that will be kept over a year, you need 14% moisture content. Try not to overdry the grain lower than 14% because you are reducing the weight you have to sell. Low moisture (14% or less) prevents mold from starting to work on exposed cracked kernels.
• Level the corn. By Jan. 1, bins should be cored and leveled so the fans can manage the grain temperature. Coring should be done to take half of the peak out of the bins and then leveled. This removes foreign material that will spoil first and reduce airflow through the center of the bin. When the bin is leveled, the fan will push a more uniform warming or cooling front through the bin. If the cored loads taken to town are of high quality, then the rest of the bin is grain that will keep.
• Control insects. Corn is food for livestock, people and insects. Long-term storage provides an environment that bugs often exploit. Grain temperatures below 20 degrees F will kill insects and eggs. While management of the grain in the bin below freezing is most critical, ISU grain storage specialists advise chilling the bin below this level in January and February to kill the insects and eggs that may be present in the grain and in foreign material below the drying floor. Choose days with no precipitation to chill the bin completely.
• Manage grain temperature. Temp-erature is the most important tool you have to manage and store grain for the long term. After you have killed any insects by chilling grain to below 20 degrees, you need to warm it up above freezing in April. For long-term storage you should warm it up to just below 40 degrees and try to keep it there through the summer. Covering the fan will help prevent the convection currents that will develop with cool core temperatures and hot outside conditions that will occur in July and August. Grain in the bin should be monitored twice a month through winter and spring and weekly during the summer.
Smell of success
Bins should be checked on top to be sure no crust is developing due to moisture migration. Fan covers should be removed and the fan run for a minute to smell the first air coming out of the grain, ensuring it smells pleasant. This will require two people — one in the bin and one at the fan control. If the corn does not have that clean, pleasant smell,then there is a problem.
Source: Iowa State University
This article published in the February, 2016 edition of WALLACES FARMER.
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