What was the moisture content of your soybeans when you harvested them?  13%?  11%?  Less than 10%? As moisture quickly declines in ripe soybeans, market weight is lost and that can mean several bushels per acre.  Multiply those lost bushels by the cash price and you realize it can eat into profitability.  How do you recoup that money?  Putting the garden hose in the top of the bin is not legal, so is there anything that can be done?

When you lost at least two bushels of soybeans per acre because of low moisture, you lost at least $25 and that may have meant the profit on the field.  Warm dry weather can ripen a crop, and ripen it too fast for harvesting.  The Food and Drug Administration prohibits the physical addition of water to grain, and getting caught can mean federal penalties.
• You cannot put the lawn sprinkler next to your truckload of dry beans and turn it on.
• If you left the tarp off the truckload of dry beans and it happened to rain, well…..
• If your bin full of overly dry soybeans needed to be cooled with the dryer fan, and the humidity happened to be 70% or more, that is just something you cannot control…so….

North Dakota State University grain quality specialist Ken Hellevang says the latter is an example of re-wetting grain that can be accomplished, if you have enough time, humidity and airflow.  Moisture will flow out of the bin on a day with low humidity, and you will lose bushels.  But managing the moisture with a humidity gauge and strategically controlling the fan will help regain some of the lost bushels due to dryness.  He wants you to know the moisture does not change throughout the bin during the process, “Instead, a rewetting zone develops and moves slowly through the bin in the direction of the airflow.”

The unfortunate aspect is the fact humidity is not high in the fall, and now is a difficult time to find humidity high enough to force into your bin of overly dry soybeans.  If you find a day with high humidity, realize that you are endangering the quality of the beans in the bin, if they get too wet to be stored safely.  The best help you have are stirring augers on the bin to blend the grain.  You can also empty the bin, move it through a grain handling system, and achieve some limited mixing.  Also beware that overly aggressive re-wetting can cause the beans to swell and that will damage a bin.

Hellevang says if your beans have less than 10% moisture, controlling the aeration fan so it runs only when the relative humidity is greater than 55% will achieve rewetting.  Your bin may have a humidistat that could turn on the fan whenever 55% humidity was reached.  Night time humidity is usually higher than daytime, so nighttime use of the fan may be an option.

Too much of a good thing can push the moisture beyond the stage of stability, and your beans could overheat and spoil if they become too wet.  Hellevang suggest two options to prevent that:
1) Add a second humidistat that stops the fan when the relative humidity reaches very high levels.
2) Install a microprocessor-based controller that monitors temperature and humidity, and runs only when air conditions will bring the crop to the desired moisture content.

Your success depends on the airflow per bushel, says Hellevang, and the weather condition.  You will do the best job when the airflow if greatest, the air is warm and humid.  He defines that as occurring in a drying bin with a perforated floor and at least 0.75 cubic feet of airflow per minute per bushel of grain in the bin.  But even at that “best” rate, it may take a month for the front to move through the grain, and that is a lot of hours for the fan.

If you have some reluctance to engage in re-wetting, remember than overly dry beans will split with handling and your market price may be docked because of that.  When handling overly dry beans, operate conveyors at slower speeds, and minimize heights at which beans drop.

Summary:
A dry summer and fall may have ripened soybeans faster than you could reasonably harvest them; subsequently their moisture level in storage may be well under 13%.  Overly dry beans will result in lost bushels at the elevator, but can be re-wetted with strategic use of a dryer fan on days with higher levels of humidity.  Too much can cause the bin to spoil, but if controlled, the process can restore moisture to the grain and dollars to your pocket.

Source: FarmGate blog