-Farm News photo by Karen Schwaller
Despite studies that claim corn yields overall will be declining in the future, ISU researchers are finding reason to be positive about the way yield predictions are headed. Constantly-changing and better corn hybrids — along with better precision farming practices — are only two of the reasons behind their findings.

CALUMET–The extended outlook for corn yield appears to be promising, according to Sotirios Archontoulis, Iowa State University agronomy professor who spoke to a group of producers at a field day in Calumet this summer.

Archontoulis said studies have been conducted by research groups, and have shown that corn yields in the future will decrease, primarily due to climate change. He provided a link (dated June 2025) that argues that theory, and that crop adaptation will not be sufficient to keep up crop yields: https://www.nature.com/articles/s41586-025-09085-w

But Archontoulis said research conducted at ISU does not support those yield-drop findings.

“To predict the future is difficult, but we strongly believe yields are going to keep increasing–for the next 10, 20 (or more) years I don’t see any reason that yields would decline unless there is a major disruption in crop production–like no new hybrids, no fertilizer, or it stops raining. Farmers are continuously adapting and there is room for further progress to be made.”

The ISU-predicted increase in corn yield, he said, would culminate from many things, but mainly from the combination (interaction) of better hybrid production annually, with agricultural management (including effective planting dates, effective fertilizer application, adequate soil drainage, population rates and precision planting), and a climate that supports the corn hybrids that continue to be developed by industry breeders.

Archontoulis said ISU studies gathered USDA/NASS survey data from around the Cornbelt–from western Nebraska to eastern Ohio, and from the Dakotas to south of Indiana and into Illinois from the years 1980-2022. They took that information and experimented with nine different climate models and scenarios of carbon dioxide emissions, along with agronomic management.

“One thing we could see is that planting dates are going to get earlier,” said Archontoulis. “As planting dates get earlier, farmers may go from planting 105-day corn to 108-day corn.”

He said as that happens there will be changes in fertility as well, and that as the date-driven scenarios came together, one thing was clear–that yields will be going up across the landscape.

“Iowa stood out as good and strong–but we saw some (increasing yield) issues in Nebraska and Kansas because we don’t know what will happen with irrigation,” he said.

Archontoulis said early- to mid-July (this year) was an important time for corn plants, as there was a three-week window during that time when corn plants absorbed the maximum possible amount of CO2 from the atmosphere, and the maximum possible amount of nitrogen from the soil, based on the size and condition

Archontoulis said the USDA/NASS Iowa corn bushel prediction for 2025 is estimated at 222 bushels per acre (bpa), adding that these predictions have been close to accurate in recent years. For example, their August 2024 forecast called for 209 bpa, and the statewide average was 211 bpa. The 2023 August forecast called for 203 bpa, while the numbers came in averaging 201 bpa. The 2022 August forecast landed at 205 bpa, with the actual statewide average 200 bpa.

“In the ballpark, I think they are right. We are going to have incredible yields in corn,” said Archontoulis, adding that new hybrids strive to create corn that creates greater yields through better water, stress, disease, pest and wind tolerances. The kickback is that they are also more expensive, he said.

He said hybrids change every couple of years, and with variables including population rates, he sees a promising extended future in corn yields.

“We have plenty of room to make progress,” Archontoulis said about working toward increasing corn yields every year.

Archontoulis said while the corn crop looks good going into harvest, he encourages farmers to be realistic when imagining what the true yields could be. While comparisons in previous years saw USDA/NASS predictions to match what actually came out of the field, yield monitors may not always tell that story. Still, he said the growing season in many parts of Iowa has been unique in that the previous year saw historic flooding.

“I don’t remember any year in the past where we have started the (growing) season with a full soil moisture profile,” he said, adding that some parts of the state experienced standing water in fields and nitrogen management.

Archontoulis said fields “look great” as of mid-August and he sees great yield potential, but he doesn’t think records will be broken in every field this fall.

“Yields are going to be very good, but in some cases we may see some surprises,” he said, adding that all a farmer can do is the best with what he has to work with.

“Farmers are doing an amazing job,” he said. “They have an unbelievable task of making (copious) decisions within a year and maximize their profits. It’s a very difficult equation, and they don’t have simulation models (to help them compare and decide)–they use their brains.”