MOUNT CARROLL – A lot of work goes into predicting crop yields. Science, data, research, historical records – and folklore.
Combining all those gives experts a baseline on which to build their predictions, such as the one S. Elwynn Taylor made Thursday in Carroll County.
The outlook? Early estimates are that this year’s crop yield in the Corn Belt will remain above average for the fourth year in a row.
Taylor, an agricultural climatologist with Iowa State University in Ames, Iowa, spoke at the Carroll County Farm Bureau about the effects of weather and climate cycles on crops.
It’s a given that weather plays a major role in crops’ success or failure, but Taylor also bases some of his work on previously observed trends and patterns in nature, such as comparing historical droughts and record-yield years against tree ring data.
He also advised checking with local folklore, such as the idea that rain will take place 90 days after a fog.
Turns out there’s some truth to that.
Since the changeover from winter winds to summer winds usually occurs in late March, warmer and wetter air can sometimes be expected 90 days after a fog.
“When you see widespread fog in January, you’re seeing the breath of the Gulf of Mexico. ... So, yes, fog early does raise the possibility of an early planting season,” Taylor said.
Farther south, a weak El Niño is developing off the west coast of South America, but it will need to be larger to really have any effect. The pattern can cause wetter-than-average conditions along the Gulf Coast, and drier conditions in the Ohio Valley.
While Taylor said the early outlook is good, he won’t start making more specific state predictions for yields until about mid-April.
“We usually know by the middle of April what the weather patterns will be like for summer,” Taylor said.
Since the southerly air flow in the spring will travel up from the Gulf of Mexico, Taylor will often look to Arkansas for a sense of what to expect for Midwest planting opportunities.
“If Arkansas is sopping wet in April, it will be sopping wet in planting time here. It’ll catch most of the Corn Belt from the center of Iowa to Ohio. It’s the only month Arkansas is a forecaster for weather here,” Taylor said.
When trying to assess planting risks, Taylor advised, farmers can check a number of websites. One at mesonet.agron.iastate.edu/plotting/auto helps farmers compare the upcoming year with an analog – a year in which weather resembled the upcoming year.
Farmers also can visit mygeohub.com/groups/u2u/acv to track their county yields and compare them with other counties and states.