Estimating drying times for binned corn and natural air  - 2009-11-05

I have received numerous calls from corn producers  harvesting corn well above the recommended 15% moisture content for long-term storage and/or to avoid being docked by the grain merchandiser. Producers with drying bins and aeration fans capable of producing at least 1 cfm/bu are wondering how long it will take to dry their corn to 15% moisture using ambient (unheated) air.

The time to dry corn, or any grain, depends on a number of variables:

The initial moisture content of the grain, %
The desired moisture content of the grain, %
The ambient air properties ? temperature and relative humidity
The airflow through the grain in the bin ? cubic feet per minute per bushel
Whether the incoming air is heated before passing through the grain
Using a grain drying program, I ran several scenarios to estimate the time it would need to dry corn (see Table 1). It estimated the days to dry corn in a grain bin using natural air and 1 cubic foot per minute per bushel of grain in the bin.

As you can see in Table 1 at http://cropwatch.unl.edu/web/cropwatch/archive?articleID=1990301, weather conditions are a huge factor in how long it takes to dry grain.

 Tom Dorn
Extension Educator in Lancaster County