Weather’s impact on agriculture is constant. From too much precipitation to not enough heat, a season largely hinges on what happens meteorologically.
Increased weather volatility has become a major variable throughout the crop season, causing changes in the way the season is viewed. Eugene Takle, an emeritus professor of agronomy at Iowa State University, said the biggest change over the years is the length of the growing season.
“It’s probably the most notable and important way climate change has impacted agriculture,” Takle said.
However, the longer growing seasons aren’t necessarily a bad thing at the moment for Midwest farmers, Takle said. As seasons have stretched out, yields have consistently increased. Takle cited a study that credited 28% of the increase to better weather.
“It’s an advantage for farmers to have this longer growing season,” Takle said. “You can plant longer-season hybrids which tend to yield better, and heat hasn’t gotten in the way yet. We haven’t suffered from the disadvantage of the increasing temperature in the planet.”
He said the main reason the Midwest hasn’t seen the major increases in temperature is due to increased average rainfall, which has suppressed summer heat on average.
Takle and his Iowa State meteorological colleague William Gutowski wrote a paper calling the Midwest the Goldilocks climate due to these circumstances, referring to the familiar fairy tale of the three bears. The early-season rains, timing of humidity and lower summer heat make it just right for crops.
Takle and Gutowski said it’s not all perfect, though, as the frequency of the spring rains may get in the way of planting. That means farmers may have to adjust by getting the crop in the ground quicker and more efficiently to avoid planting in soaked soils.
“The number of field work days is reduced,” Takle said. “Farmers are buying bigger machinery and working 24/7 to get the crop in the ground.”
Along with frequency, they said the intensity of rain events is notable. Seeing a 5-inch rain is not uncommon now, Gutowski said. However, the rains don’t linger for many areas, as the pendulum has often swung back to dry conditions, as seen with western Iowa in 2020.
“Despite the fact our precipitation totals seem to be increasing, it seems we can get more of these ‘pop-up droughts’ that only affect half the state or a quarter of the state,” Gutowski said.
Gutowski said the increased intensity of rain events has also led to the installation of more sub-surface drainage tile to help transport soil water, as the increased precipitation can create soil erosion.
“Farmers are responding,” he said. “They are widening their grass waterways and putting in cover crops. These measures they’re taking, they are responding to what they are seeing that they didn’t have to cope with 30 or 40 years ago.”
Another major change has been wetter and milder Novembers and Decembers in recent years, Takle said. That has led to more grain drying as farmers prepare to put the crop in the bin, but when it’s warmer out, the additional moisture may cause a problem.
“When you get these really warm, humid events, what you are doing is blowing air that’s maybe 60 degrees Fahrenheit into these bins and the dew point may be 50 or 45 degrees,” Takle said. “You are blowing moisture into the corn inadvertently if you aren’t watching the dew point. That’s creating a negative condition that will lead to mold and toxin developments that can happen.”
Takle said longer-season hybrids and more drought tolerance for those “pop-up droughts” in the seed marketplace help farmers take advantage of the conditions in the Midwest. Essentially, preparing for everything is his advice.
“Staggering and planting more than one hybrid and more than one growing season hybrid and staggering pollination periods,” Takle said. “You don’t want to have all your fields pollinating at the same exact time because that could make you vulnerable to a drought that happens over a seven-day period.”