Plunging Temperatures Creates Concern for Wheat

Experts say wet soil, snow cover should help protect wheat crop.

Published on: Jan 11, 2010
With temperatures falling to near record lows this week, wheat farmers have every right to be concerned about the well-being of the fledgling crop. The good news is that, with ample moisture in Kansas wheat fields, the crop should weather the extreme cold fairly well. The bad news is that, with two months of winter left and snow cover being compromised by harsh north winds, the potential for damage exists.  

Lack of snow cover in western Kansas, combined with record low wind chills could combine to damage the 2010 wheat crop. Justin Gilpin, Kansas Wheat chief executive officer, says the early January cold snap could very well test the winter-hardiness of popular wheat varieties.
 
"When soil temperatures decrease to about 12 degrees, I get nervous," says Jim Shroyer, Extension agronomist at Kansas State University. "When they fall to single digits, I know without a doubt there will be winter damage."
 
There is a caveat, however: "Soil moisture holds in a lot of heat, so even if we get temperatures at 0 or below for a few days, the wet soil shouldn't get that cold," says Shroyer, who adds that wheat fields blanketed by snow also are insulated from the cold.
 
The wheat crop has "hardened", or developed good winter-hardiness by being exposed to gradually colder temperatures throughout the fall and winter.
 
He is much more concerned in cases where wheat was planted late and root establishment is poor, or when fields are dry or soils are not protected by snow. Winterkill is possible if soil temperatures at the crown level - about one inch deep - get down into the single digits. If the soil is dry and there is no snow cover, the potential for damage increases exponentially. In the Jan. 4 Kansas Crop Report, Kansas Agricultural Statistics Service estimates that 12% of the crop has minor wheat and wind damage.
 
Whole fields likely will not be totaled. Rather, exposed slopes, terrace tops or low-lying regions are more prone to winter damage. Shroyer is particularly concerned in cases where young wheat has suffered through several freeze-thaw cycles, and the upper inch of soil gets dry. When the cold north winds begin to blow, the crown root system is subject to damage from desiccation, he explains.
 
At the beginning of the New Year, a majority of fields in central and eastern Kansas were covered by snow. In western Kansas, wheat fields are protected by damp soils, says David Schemm, vice president of the Kansas Association of Wheat Growers and a farmer near Sharon Springs. "The wheat I've seen is hugging the ground tight and has its winter clothes on," he says.
 
However, regardless of temperature, moisture condition or wheat plant maturity, Shroyer says farmers are at the mercy of Mother Nature.
 
"You can worry and get ulcers, but there is nothing you can do about it. You just have to remember these cold spells occurred and if, when the wheat starts greening up in eight weeks it goes backwards, you'll know the reason is due to winterkill." 

Source: Kansas Wheat