Spring is a critical time for stored grain management. It's important to check condition of stored grain now and take any necessary actions to correct grain temperature or moisture before the weather gets too warm.
First, check grain at the top center of the bin for evidence of moisture migration. Uneven grain temperatures that develop during winter cause convection currents and diffusion, which in turn move moisture to the top center of the bin. Any grain rewet by moisture migration will mold or become infested by insects when the temperature increases this spring. If you find an area of wet grain, either remove it from the bin, or scatter it across the grain surface and try to dry it using the bin's fan.
All grain in the bin should be down to about 14% moisture for storage into summer and 13% for storage beyond summer. If grain moisture is not down to these levels, feed, sell, or dry the grain in the next couple of months.
In many cases, natural-air drying is not completed before winter, and needs to finished in spring. Probe natural-air drying bins to locate the drying front and to determine the moisture of the wet grain. If the drying front is at least half way through the bin and all grain is less than about 22% moisture, chances of success are good. Use the following moistures and dates as a guide to restarting the drying fan.
If the grain is dry enough for spring and summer storage, check grain temperature at several depths and locations to make sure it is uniform. Aeration is needed when there are temperature differences of more than about 15 degrees F in different parts of the bin. If you decide to aerate, make sure you do it before average outdoor temperatures (day time high plus night time low divided by two) get much above 40 degrees F. As long as grain is less than about 40 degrees, molds and insects are relatively inactive.
Because condensation occurs when you aerate this time of the year (grain temperature is below the dewpoint temperature of the air), it is important to operate the aeration fan continuously to move the temperature front and layer of condensation all the way through the bin. For a typical storage bin with a small aeration fan, this will take five to seven days. In bins equipped with drying fans, temperature fronts can be moved through a bin in a day or so.
Even if grain is dry and cool going into spring, it is still important to check bins every week. Mold and insect problems can develop very rapidly in warm weather, but catching these problems early will minimize spoilage losses.