Maintaining quality of direct-from-field binned corn in early spring

Corn harvested and placed directly into the bin last fall requires special consideration especially if it will be marketed late in summer.

Last fall we saw corn grain moisture levels at 15 percent and below coming directly out of the field in Michigan. This really reduced corn drying costs last fall. However, corn harvested and placed directly into the bin may cause some challenges when it comes to grain quality, particularly if it is being stored for marketing later in the summer.

Part of the reason that corn came out of the field so dry last fall was because dry conditions, as well as warm temperatures, cause early dry-down of the crop. Variability in soil moisture holding capacity, pockets where wet conditions early in the season may have delayed crop development and other factors can cause variability in the moisture of the grain. This moisture can migrate with air movement in the grain bin, causing pockets of grain that may be susceptible to molds. This may be particularly true of corn that was damaged by western bean cutworm feeding which caused ear molds in 2010. With temperatures on the rise in March, it may be prudent to carefully keep an eye on grain quality in storage bins where corn was placed in storage directly from the field. This grain may not be a good candidate for storage into the warmer summer months.

Some general guidelines for checking the quality of stored grain include monitoring grain temperature and running the aeration fan and checking for musty odors near the vents. Also check for grain spoilage in the upper center portion of bins, where moisture often migrates due to temperature differentials along the outer bin walls and the center of the grain mass. Be careful when doing this. If grain has been removed from the bin, be aware that bridging can occur across the bin’s surface, creating a falling or suffocation hazard. Samples can also be collected at various depths to check grain quality.

Aeration of the grain mass to maintain cool temperatures can be accomplished if the ambient air temperatures remain cool enough to move a temperature front through the grain mass. Be cautious of running the fans in excess of the time needed to create uniform grain temperatures, as this can increase grain moisture if the relative humidity is high. Coring the bin can also help to remove fines from the center of the grain mass to the upper surface of the bin, promoting better airflow when aerating the grain mass.

The decision to either warm the grain mass if longer term storage is desired often depends upon the quality of the grain in the bin at this time of year. If you plan to store grain into July and August, it may be wise to warm the grain up to the 50 degree F mark as temperatures warm into spring and early summer. This aeration strategy is often started as the average ambient air temperatures warm up 10 to 12 degrees above the grain temperature in the bin. Keep in mind that corn that has not been run through a dryer may be at greater risk for spoilage because of potential differences in moisture in the grain mass.

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