Check grain bins for varied moisture conditions

By Dan Martens
Extension Educator

We talked about stored grain fumigation at our pesticide applicator workshops recently. A farmer came up during the break to talk a little more about grain storage issues. He thought having good field drying conditions in the fall could give people a false sense of security about stored grain.

I suggested in some cases, variable moisture conditions across fields might have made for variable moisture condition in grain bins. Some people also found more grain damage in parts of the field that were very dry, and that can contribute to potential for spoilage and insect issues.

In any event, it’s good to do what you can to check the condition of grain in storage. The easiest step is probably just to check for signs of condensation at the top of the bin, on the surface of the grain and on the walls or roof of the bin.

We have a little better chance to monitor the grain where we are feeding out of bins. Some bins are equipped with temperature sensing cables. And there is some opportunity to use a grain temperature probe. Granted, it’s not easy to run a probe through 15 or 20 feet of grain.

I’m reminded of an article by North Dakota State University grain storage specialist Ken Hellevang a couple of years ago — pointing out that the sunshine solar energy hitting the south side of a grain bin on Feb. 20 is twice what it is on June 20 and the solar energy on the roof is about the same as on June 20.

Fortunately, grain has a good insulation value. Warming of the grain is usually limited to a couple feet near the bin wall and at the top of the bin. Unfortunately, the insulation qualities also mean that temperature cables can miss hot spots a few away, but the cables certainly improve the chance of picking up on a problem in larger bins.

Hellevang says the goal is to keep grain in storage cooler than 40 degrees for as long as we can. Keeping grain below 40 significantly slows any insect or spoilage development. Aeration should not be needed if you’re confident the grain temperature is staying below 40 degrees.

For people using natural air drying, if there is drying that needs to be done in the spring, the goal is to do this drying once the average outdoor temperature reaches about 40 degrees. That’s usually early in April. Watch how this year’s weather unfolds. The goal is to get the grain dry before it warms up enough so spoilage could occur faster than you can get it dried.

Most of the crop probably got plenty dry in the fall. Even then, it’s good to check bins occasionally through the winter season.

Winter forage notes

Bruce Anderson, University of Nebraska forage specialist, shared field trial data showing that corn planted after alfalfa has a yield advantage that is more than what can be accounted for from nitrogen credits and rotation effect. This suggests alfalfa has beneficial effects on the soil beyond nutrients left behind.

There is a fair amount of talk these days about cover crops, third crops, soil health and related topics. It’s interesting to note that alfalfa, a crop we’ve had around for a long time as a valuable feed resource, likely provides some of the benefits we’re looking for with other things these days. We certainly are also learning new things about other cover crops.