March 20, 2015
Checking Stored Grain
Record highs last week and very comfortable weather predicted for the near future has many farmers thinking about preparing to plant their 2015 crop. While warmer temperatures are a welcome relief, they also pose some problems for last year's crop.
This time of year can be a challenge for folks with on-farm stored grain in a normal year, but great temperature swings can potentially reduced the quality of stored grain. We never want the condition of grain to deteriorate while it is in storage, but that is even more important when commodity prices are already low. It will be more important than ever to monitor and manage grain stored on the farm to reduce or eliminate further deterioration in its condition.
Periods of warm weather like those we had last week and are predicted in the week ahead will warm grain near the bin walls, particularly on the south and west sides of the bin... while grain on the north side and near the center of the bin remain cooler. This uneven warming causes moisture movement within the grain and condensation in the cooler parts of the bin.
If the grain temperature is below freezing, moisture will freeze between the kernels, forming a block of frozen grain. When the bin is aerated, air will move around, rather than through, these frozen areas. When that grain eventually thaws, it will create a wet area in the grain mass and increase the likelihood of spoilage.
So how do you avoid this problem when you can't control the weather? Every couple of weeks you should check the grain temperature with a probe thermometer. Check the temperature of the grain around the bin walls and also near the center of the bin. If there is more than a 10 degree difference between any of the readings, turn on the fans to push a temperature front through the grain and equalize the temperature.
As the grain is gradually warmed this spring, try to keep the grain temperature within about 10 degrees of the average outside temperature. Whenever you turn on the fan, use this as a time to monitor grain condition. Have someone else turn on the fan while you are positioned by a roof vent or opening in the roof.
If that first blast of air coming out the vents is musty, more humid, or warmer than the outside air, this indicates a problem developing in your grain. You need to run the fan continuously to reduce the problem, monitor this bin more frequently, and then use or sell this grain as soon as possible.
Two important safety consideration. First, before entering a bin, be sure you have a safety harness or rope connected to yourself and have someone outside the bin that can pull you to safety if you should break through a crusted area. Grain can bridge and form air pockets below the surface. If you break through the bridge, it is likely you will not be able to get out on your own.
Second, there was a lot of mold in corn when it was harvested last fall. This can't get better while the grain is stored, but it can get worse. If you are monitoring the exhaust air when ventilating a bin or if you are entering a bin to check the grain temperature, wear a respirator to prevent inhaling mold spores. Failure to protect yourself from inhaling mold spores can lead to Farmer's Lung, a debilitating respiratory disease common among farmers.
For more information about on-farm grain storage, contact your local Nebraska Extension office.