The ugly trifecta of 2019 — late planting, high-moisture corn and plentiful rain and snow — has left many farmers facing unharvested cornfields into December and possibly beyond.

Of all the agronomic sins this year has forced onto the landscape, cornfields left standing deep into the winter is perhaps the one farmers dread the most.

“Nobody in my part of Ontario, and, I presume, the rest of the province, wants to leave corn out for the winter, especially this year,” said Dan Petker, who farms in southern Ontario, Canada. “Surrounded by the Great Lakes means lots of moisture-laden air, lots of snowfall and lots of wind.”

Even farther south, the idea strikes fear in the heart of north-central Missouri farmer Kyle Samp, who was forced to harvest some fields in January last year due to overly wet conditions. “Even that long makes me so nervous,” he said. “You had better have some pretty good stalks and good-quality grain to start with.”

Farmers facing standing cornfields should know their risks. Winter temperatures allow for limited drying in the field, and yield loss from lodging, ear drop and wildlife feeding is a likely risk. Finally, depending on your policy, crop insurance may not follow your crop through the winter months.


In Wisconsin, farmers have up to a third of the corn crop left to harvest, and high-moisture corn is very common, noted University of Wisconsin Extension corn agronomist Joe Lauer.

The costs of drying that corn down mechanically to the desired 15% for storage are significant, he noted. The research suggests drying costs for a single point of moisture range from 3 cents per bushel for on-farm drying to 6 cents per bushel for commercial drying.

“If you have 30% moisture corn and you multiply that out, you’re looking at 45 to 90 cents in extra costs, which takes the profit out pretty quickly,” Lauer noted.

As such, the possibility of letting Mother Nature do the job in the field may seem attractive, but growers should be aware that drying rates plummet in the winter months, especially in the northern Corn Belt, he added.

“Generally, once you hit Dec. 1, there isn’t a lot of moisture loss occurring until March or April of the following year,” he said. A 2009 study by Lauer and former Wisconsin Extension agent Nick Schneider found that, in Wisconsin, 22%-moisture corn stayed at that level through December and January and only dropped to 16% and 10% in March and April, respectively.

For other options on air-drying corn in the bin during winter months, see this University of Nebraska article:….


A lot can happen between December and April. Wind, snow and ice are a significant possibility for most growers in the Corn Belt, as are foraging wildlife such as deer. A wide range of lodging, ear drop and kernel shattering are possible each winter, which makes predicting yield loss almost impossible, Lauer noted.

Lauer and Schneider tried to conduct research on this by measuring yield loss in standing cornfields in Wisconsin in 2000 and 2001. The results varied widely. In the snow-heavy year of 2000, the researchers measured yield losses ranging from 38% to 65%, depending on which month the corn was harvested. In the milder winter of 2001, yield losses ranged from 5% to 18%.

“The spread of what can happen is really wide, and the bottom line is the longer the corn is in the field, the more risk you take on,” Lauer said.

Keep in mind that late, wet planting and disease has left many fields with serious quality issues this year.

“Stalk integrity this year is terrible, and most corn would not be standing by spring harvest time — mid to late April,” Petker said of his Ontario region.

Ear molds and other quality issues could also create problems. Mold development can continue until outside temperatures drop below 40 degrees Fahrenheit or moisture drops below 20%, according to North Dakota State University Extension agricultural engineer Ken Hellevang. See more here:….

University of Minnesota Extension educator Angie Peltier and North Dakota State University Extension agronomist Joel Ransom cautioned growers of another potential victim of overwintering corn: your 2020 crop.

“When deciding on keeping corn over the winter, remember that dealing with corn residues after a spring harvest will likely delay any spring land preparation and planting, (and) that could put your 2020 (crop) at a disadvantage,” they wrote in a joint university newsletter. Volunteer corn could also complicate weed control in the following crop.


Don’t assume crop insurance will follow your corn crop through the winter months. According to USDA’s Risk Management Agency, basic crop insurance policies end their coverage period when any one of the following scenario occurs first:

— Total destruction of the insured crop.

— Harvest of the insured crop.

— Final crop loss adjustment.

— The calendar date contained in the Crop Provisions or Special Provisions for the end of the insurance period (Dec. 10 for corn as a grain crop).

— Abandonment of the insured crop.

USDA defines “abandonment” as: “Failure to continue to care for the crop, providing care so insignificant as to provide no benefit to the crop, or failure to harvest in a timely manner, unless an insured cause of loss prevents you from properly caring for or harvesting the crop or causes damage to it to the extent that most producers of the crop on acreage with similar characteristics in the area would not normally further care for or harvest it.”

Growers with standing cornfields should check with their individual crop insurance agent, Peltier and Ransom stressed. “Please keep in touch with your crop insurance agent should either you suspect an insured loss or the Dec. 10 deadline approaches,” they wrote.

For more details on standing corn risks and drying costs and breakevens, see this article from the Minnesota scientists here:… and Lauer and Schneider’s work here:….

Emily Unglesbee can be reached at

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Source: Emily Unglesbee, DTN