Don’t let an early fall freeze ruin your year
On Aug. 27, 2013, temperatures blistered the ground around Des Moines, Iowa, at a near-record 102°F. In fact, the late August heat wave pushed temperatures into the upper 90s or higher around much of the Midwest. Corn leaves curled up and farmers wiped the sweat from their brows.
Yet the No. 1 concern on many minds was how early the first killing frost would arrive.
Crop market strategist Ted Seifried says the cooler, wetter spring made this conversation inevitable—late summer heat wave or not.
"A cold and wet spring did two things," he says. "One, it recharged subsoil moisture levels in most areas after a severe drought last year. Two, it caused massive planting delays. So, it was a bit of a bittersweet spring."
Timing is everything, and it has generally not been on agriculture’s side in 2013. A late-planted spring is not a recipe for disaster by itself, but throw in a cooler-than-normal May, June and July and chase it with the aforementioned August heat wave, and suddenly a little concern just might be justified. Fortunately, the Southern Corn Belt already has harvest put to bed by October, but much of the upper Midwest, from the Dakotas to Michigan, will be watching the thermometer.
The trouble with predicting early frost is that it’s not reliable to do so until about 10 to 14 days out, explains Laura Edwards, an Extension climate field specialist with South Dakota State University.
For example, although a hot spell in August will build much-needed growing degree units (GDUs), it’s not an accurate predictor of a late frost, Edwards says. The opposite is also true, she says—a cool August doesn’t correlate to an early frost, either.
"From year to year, it really varies quite a bit," she says.
When the first frost will land is anybody’s guess, but Edwards feels sympathetic for farmers in the upper Midwest who need that date to come as late as possible.
"We’re all crossing our fingers for an average or late freeze date," she says.
Early fall freeze is one of six climatic calamities covered by Total Weather Insurance (TWI) policies for corn available from The Climate Corporation. The company’s corn TWI policies issue payouts to policyholders based on any GDU shortfalls that exist when the first killing freeze of the fall occurs.
This shortfall is calculated by looking at planting date, relative maturity and to-date GDU accumulation, says director of agronomic research Jeff Hamlin. Using this and other data, Climate Corp has created a unique look at fall freeze risk with a map that shows this risk to corn in each part of the Corn Belt, he says.
"This resource is going to help answer the big question right now—is the crop going to get to black layer before the first killing freeze," he says.
The freeze risk map is updated at insights.climate.com every few days with additional forecast information.
You can’t control the weather, but you can control how you react to the weather. Getting slapped with early frost is no different.
For example, if you were dealt a killing frost while your corn crop is still in the field, that grain will need to be managed a bit more closely, says Sam McNeill, University of Kentucky Extension associate professor.
Before frost-damaged corn goes into storage, it must be properly dried and cleaned, McNeill says. The frost "puts corn in a holding pattern," he says, which means moisture content tends to be higher, and higher moisture levels mean higher drying costs.
For today’s average dryer (rated at 2,250 Btu/lb. of water removal at 10 points) and LP gas at $1.50 per gallon, expect drying costs to run about 16¢ per bushel at 20% moisture content. At 25% moisture content, that number jumps to nearly 29¢ per bushel.
Remember that after the grain has been stored, it has a diminished shelf life, McNeill adds.
Sensors and other monitoring technologies cost extra, too, but McNeill thinks the investment is worth it.
Remember the tremendous asset that your grain bin could be holding; he reminds farmers that a 100,000 bu. grain bin could easily be carrying a half-million dollars’ worth of grain.
"You should be investing in this technology anyway—but especially in instances where you’re storing damaged grain," he says.
In certain scenarios, you might be able to move up harvest to jump ahead of the first killing frost, McNeill says.
"That’s a hard call," he says. "It boils down to managing risk and how close the crop is to being ready for harvest. Grain is easier to manage in the bin than in the field. It’s a decision you should make on an individual basis."
DuPont Pioneer agronomists note three reasons to avoid an excessive delay of harvesting immature corn:
- If you delay harvest, you will finish later, resulting in less time for fall fertilization and tillage.
- Limited fall fertilization and tillage in turn limits options for crop rotations next spring.
- Drying corn when it’s 20°F outside requires more energy (and is therefore more costly) than drying corn when it’s 40°F outside.
That last point sticks with McNeill as well; he says farmers should always focus on safety, but dealing with a frost-damaged crop heightens the chance for a few specific dangers.
"As we have more quality concerns, we tend to have a higher incidence of entrapments and other safety issues," he says. "You just have to be more diligent during drying and storing. It changes the game."
For three handy tools that will help you calculate GDU accumulation, local frost probability and more, visit www.FarmJournal.com/early_frost
You can e-mail Ben Potter at firstname.lastname@example.org.
- October 2013