By Lauryn Higgins
Close to harvest time, in late spring, the wheat fields of Kansas are usually swaying in the warm air like ocean waves. But not this year. “We knew last fall when we planted, we would need near perfect conditions going forward to raise a good crop,” said Mike McClellan, who’s been farming 1,500 acres of wheat in Palco, Kansas, for nearly 30 years. “That did not materialize.”
In fact, he said, this year’s crop was the worst he’d ever seen — sparse and stunted. His plan: kill all his wheat with herbicide and collect the crop insurance.
It’s been a record-breaking year for hot, dry, windy (HDW) events in the Midwest, with Kansas — the nation’s largest winter wheat producer — hit worse than any other state. The events, in which all three conditions occur simultaneously for a prolonged period, inevitably lead to drought and lowered grain yields.
Recently, researchers from Kansas State University quantified the impact of HDW events on the state’s winter wheat yields between 1982 and 2020, finding that for every 10-hour period that a wheat field experiences such an event, yield declines by 4 percent.
The team also analyzed how different combinations of weather affect wheat production and determined that hot, dry, and windy events, when they occur at the same time, have significantly greater negative impact on wheat yields than when the conditions happen separately.
“That precise combination of events has been increasing over the 40-year period due to climate change” and is likely to become more common over the next few decades, said agronomy professor Stephen Welch, who ran the study’s theoretical plant modeling. “That’s a key factor.”
And while it may be easy to understand how climate change contributes to extreme heat and drought, it’s the third condition that is battering Kansas wheat fields. Winds shape regional climate and influence daily weather by transporting heat and water, and as temperatures climb, atmospheric pressure increases — generating faster and longer gusts of wind.
In general, winds above 15.7 miles per hour are considered harmful to wheat, and gusts within the last year have broken records, reaching as high as 17.7 mph in some parts of the state.
In Kansas, winter wheat generally hits its most critical growth stage in the spring, when the plant is flowering and ripening. That’s also the time of year when winds have recently been at their strongest. These winds can break or bend stems, flatten fields, or damage flowers.
Xiaomao Lin, the state climatologist and Kansas State professor who led the research team, said climate change is bringing higher temperatures and less precipitation to the Great Plains, which means HDW events are likely to increase and could contribute to more frequent dust storms. Over the period they studied, the researchers found that HDW events occurred most frequently, and with the most severity, in the same agricultural areas affected by the 1930s Dust Bowl.
While practices like planting cover crops and rotating crops have improved dust conditions over the last 100 years, the southern High Plains is the windiest region in the inland U.S. and one of the driest regions east of the Rockies.
“Dry conditions, combined with heat waves and windy events, have a significant, negative impact on crop yields, livestock production, and pasture conditions,” Lin said. “This impact will be even worse under an unprecedented, changing climate in the mid-term [up to the year 2050] and long-term [up to 2100].”
A new report from the American Meteorological Society corroborates these findings. The study shows how an increase in global temperatures has driven an increase in extreme drought, potentially affecting wind patterns and ocean currents around the world.Click here to see more...