Grain Moisture Considerations | Grain Storage | Geringhoff



Some growers say that harvest timing is everything. There are substantial weather issues, crop characteristics, and grain moisture content and storage variables that create a challenge when determining the right time to harvest.

Wild cards like weather can’t be controlled, but moisture content and storage can be.

Karl VanDevender, Professor - Extension Engineer, outlines some moisture basics in a University of Arkansas System, Research & Extension report, paraphrased below:

A basic concept he reiterates is that, as a rule, dryer grain and cooler temperatures increase safe storage durations. That’s a given.Grain drying begins in the field after the grain is fully mature. A layer of tissue is formed between the seed and the plant, which blocks additional moisture and nutrient inputs from the plant.




How to field dry corn relates to the sun and air that can remove moisture and dry the grain at a rate of one-half to one-percent per day. It is typically field-dried to a certain moisture, and then harvested and marketed immediately or stored and dried further.

Drying options after harvest, in grain storage bins or containers, include; natural air and low-temperature drying, high temperature bin drying, as well as combination and dryeration.

VanDevender’s report mentions disadvantages with field drying. It can extend the time the crop is in the field with potential exposure to weather and pests. Plus, drier grain can result in shatter and losses during harvest.

Of course, different grains display differing factors. For corn, 20% grain moisture content at the time of harvest shows higher yield retention as compared to corn that falls below that level, according to Grain Retention: Every Kernel Counts, a Geringhoff Experience magazine article.

There may be costs, such as fuel and labor associated with getting out in the field when right when conditions are optimum, but yield retention can offset those costs. In addition, there can be costs to waiting, such as over-drying that may result in broken kernels, increased mold risk and other kernel damage. Dried field corn readiness can be verified with a grain moisture tester.

Proper harvest timing can pay dividends for proper moisture content in grain, helping with yield retention, quality control, and storage.

So, when does corn hit that magic 20% threshold? That depends. Climate, geography, planting timing, and other agronomic influences all play a role.

In the harsher conditions in North Dakota, for example, later planting means a later harvest. Add lots of rainfall or a lack of heat, and that growing season can get extended even further. Three farmers there point out how they managed moisture, and how equipment and environment played a role in getting things just right, including a late frost that was well timed:

“We didn’t get our first frost until October and that helped a lot,” says Kao Grubb, Powers Lake, N.D., commenting about how the crop was able to reach maturity based on that timing. “But it was coming in wet because we didn’t get much dry down. Even in November it was coming out at 25 to 30 percent or more. Even in January it wasn’t right. It finally got down to 19 to 22 percent.” It was winter. It was harsh. It was time to figure out a way to get the corn out of the field in extreme conditions. They contacted Geringhoff and the company helped make it happen.

Travis Iglehart has a farm 120-miles away from Powers Lake, and says the right equipment helped maximize yield retention when moisture was low. “It was wet late so we’re harvesting in March (at 15.5 to 16 percent moisture). The snow doesn’t bother the head, we aren’t running snow through it, just riding on top of it.”


In sum, when the conditions are right for any crop, growers need to get it off the field. There are ways to take it earlier and dry it in storage. There are ways to field dry it. The drier it gets, the more careful harvest has to be to retain yield and minimize loss. The right equipment is a powerful force that can help take that timing seriously.

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