Storing Wheat through Four Seasons?

With wheat prices being lower than anticipated, some farmers are considering storing their wheat for longer periods of time - twelve months or longer. The decision to do this should not be made in haste since many things can change over those many months. Storing good quality grain and keeping the quality good takes excellent management by the farmer. Typically, farmers store grains for periods of three to six months. With this relatively short storage interval, changes in the bin happen very slowly. As the storage interval stretches out through the warm spring and the heat of summer, undesirable elements may establish in the bin that require quick action on your part to avoid a possible serious situation.

Challenges

Grain storage pests, grain moisture, grain temperatures and maintaining grain quality will be your biggest challenges in long-term wheat storage. Grain stored at cooler temperatures and lower moisture contents can be stored for longer periods of time before quality degrades. The buildup of insects, mites molds and fungi will affect grain quality and length of grain storage. Cool, dry grain will keep longer without significant quality breakdown.

Insects, molds and mites can all cause grain to go out of condition. Cooler temperatures render most of these problems inactive. The safe grain temperatures to reduce problems are less than 8oC for insects, below 8oC for molds and below 3oC for mites. Grain moisture content of less than 13% stops growth of most molds and mites. Grain less than 10% moisture content limits the development of most stored grain pests.

Equipment

Make sure you have the necessary equipment before you consider long-term storage of wheat on your farm. At a minimum you should have the following:

• clean bin
• full aeration floor
• dry wheat
• stored grain insect treatment plan
• an understanding of the wheat Equilibrium Moisture Chart

The following graph shows the safe storage interval for different grain moisture contents and temperatures.

Figure 1. Effect of Temperature and Moisture Content on
Allowable Storage Time of Wheat, Oats, and Barley
(Source: Cereal Grain Drying and Storage, AAFRD)

Below are a number of suggestions from farmers who have stored wheat for a long time. A common comment from the people I talked to was for farmers to make absolutely sure they know what they are getting into by storing wheat for extended periods of time.

Sanitation
Clean out all old grain from inside the bin. Remove any spilled grain near the bin area. Kill weeds around the bins to prevent places for insects to hide. Treat the empty bin to kill any grain storage pests using diatomaceous earth. Never, ever put new grain on top of old grain.

Treatment
Treat the wheat as it is put in the bin with diatomaceous earth. Do not exceed recommended label rates per tonne as this will cause plugging. Diatomaceous earth, or DE, can be metered into the unloading auger or top dressed onto wagons or trucks before unloading.

Aeration
As with any stored grains you should keep the grain mass temperature close to the average outside air temperature for the season to prevent convective air movement. Use the equilibrium moisture chart for wheat to know when to operate the fans and not add moisture to the wheat in the bin.

Check the Bin
Routinely check your stored wheat bins to look for moisture accumulation, insects and off-odours. Use all your senses. Familiarize yourself with stored grain pest identification. Know your enemy.

Prepare for Cleaning
Look for someone who could clean your grain before it is shipped out in the event it is necessary. Cleaning properly done, can remove non-desirable materials.

Freeze and Leave Cold
Most of the problems with stored grains can be managed by keeping the grain cold. Insects, molds and mites are not active when it is cold. This means the problem will not get any worse. Don't be in a rush to warm up the grain in the spring.

Fumigation
A number of fumigants are registered for use to control stored grain insects. Since they are all "restricted use" products, special licensing is required to purchase and use these products. All fumigants require grain temperatures above 5oC. If you discover insects in your grain in the middle of February and the grain is to be picked up the first of March, there's nothing you can do since the grain is too cold for the fumigant to work...

Sell the Crop and buy Paper Back
Selling your crop and buying a future contract shifts the responsibility of maintaining quality to someone else. You can still try to get a better price for your wheat but you don't assume as much risk as if you stored it on your own farm.

Storing wheat for long periods of time has been done in the past. It is possible. I would not suggest the faint of heart even consider it. You need to stay on top of your grain condition and react quickly when a problem does occur.

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