Computer model helps winter wheat survival

The Winter Wheat Survival Model makes it possible to project a crop’s possibilities and allow for manageable factors

SASKATOON — Growing winter wheat and playing blackjack are two activities with almost nothing in common.

Except one thing: if you don’t know what you’re doing, it’s easy to lose money playing blackjack or growing winter wheat.

“The example I like to use is: let’s figure out blackjack by going to Vegas (but) never playing the game before,” said Ken Greer, founder of the Western Ag Group of Companies.

“The chances of actually coming (out) a winner are pretty slim.”

Similarly, with winter wheat, if a grower doesn’t understand all the agronomic factors and the rules of the game, it’s much harder to succeed.

“Cropping systems and how different crops work, particularly winter crops, it’s a different system,” said Greer, who spoke about winter crops the Farm Forum Event held early December in Saskatoon.

When producers experiment with a new crop, or something they haven’t grown in 15 years, they often select what looks like a suitable variety and grow it on a small number of acres.

In the case of winter wheat, if it survives the winter and produces a decent yield, great.

If not: back to the drawing board. Or wait another decade before trying it again.

But there’s a better way, Greer said.

It’s called the Winter Cereal Survival Model.

The model is an online simulator, which allows growers to play around with variety type, seeding date, seeding depth, fertilizer and other factors to understand what works and what doesn’t.

“We can use these simulators … to get smart before we actually have to spend money getting smart,” Greer said.

“Is there a potential with winter crops? Sure there is. What’s the first thing we have to figure out? Can we get it through the winter.”

The Winter Cereal Survival Model can be found at

Greer and Brian Fowler, a professor emeritus and retired winter wheat breeder at the University of Saskatchewan, developed the model nearly two decades ago.

In 2018, Fowler was inducted into the Saskatchewan Agriculture Hall of Fame.

The Winter Cereal Survival Model offers a live look at soil temperatures at about 15 locations (mostly research centres) across the Prairies.

At the University of Saskatchewan, for instance, a blue line on the graph shows that soil temperatures were 10 C in the fall and dropped to -5 C in late December.

There is also a black line on the graph, illustrating the cold tolerance of the winter cereal.

“The black line … is the LT50, the lethal temperature where 50 percent of the wheat will be killed,” Greer said.

For AAC Elevate, the base LT50 is -22.8 C. But the actual LT50 depends on agronomic decisions like seeding depth, seeding date and fertilizer rates.

That’s where the Winter Cereal Survival Model provides its value.

It’s possible to adjust the seeding date, depth and other factors within the model to see how it affects the LT50.

If a user selects a seeding date that’s four weeks late and a seeding depth of 1.5 inches, then the LT50 for AAC Elevate changes to -19.2 C.

The winter wheat now has less cold tolerance and is at greater risk of a winter wreck.

“You can look at what mistakes (you) can make, and what mistakes (you) can’t make,” said Greer, who compared the computer model to test-driving a car. “The real advantage of any game system is you get to drive real expensive cars without having to write a cheque.”

The Winter Cereals Survival Model is not just for winter wheat. It’s also possible to test the survivability of fall rye, triticale and barley.

Growers can also look back in time to study winter cereal survivability in previous winters.

Using Pierson, Man., in 2018, as an example:

  • With AAC Elevate, a seeding depth of 1.5 inches and seeding three weeks late, the model shows there were eight winter kill days (when temperature dropped below LT50).
  • If the date of seeding is two weeks late and at a depth of one inch or less, then there’s only one winter kill day.

The model has limitations. Mother Nature will decide if a winter cereal survives the winter or not.

Still, it’s handy to have a model to test potential scenarios and gauge risk.

“If it’s getting late (for seeding) and you’re wondering, hey, can I get away with it?” Greer said.

Looking ahead, Greer hopes to expand the Winter Cereals Survival Model so it covers all winter crops, including winter pulses and winter oilseeds.

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