Editor’s note: The following was written by Kris Kohl, Iowa State University Extension ag engineering specialist, for the Clippings Extension newsletter. The crop will soon be coming out of the field, and with the very late replant and the overall early planting of the rest of the fields, the difference between moisture content will be very wide. Also, the low crop prices have many farmers planning to store the corn and soybeans longer than in the past.
When grain is more than four moisture points different, it tends to separate in the storage pile because of flow and friction and accumulates in spots like the center of a bin, with the broken kernels plugging the air paths. Because wet grain has all the needed nutrients for bacteria to grow and their byproducts are heat and moisture from the destruction of the grain, a chain reaction can start. A wet spot as small as a basketball can spoil the whole bin regardless of size.
Moisture testers do a very good job of testing grain that is uniform in moisture. When the kernels are different, it will tend to read higher than the average because the electrical conductivity of the wetter kernels are going to be overrepresented. Hand shelling a sample for testing will often read three to four points dryer because the combine will tip many of the wetter kernels.
The tip is the last place to dry. The butt end of an ear is wetter than the tip, and second ears on a stalk are often 10 points wetter than the main ear. When hand shelling, tr.