MADISON, South Dakota — South Dakota has experienced one of the driest summers in more than 100 years and nearly the entire state has been in some level of drought during the 2021 growing season. However, the dryness varies greatly across the state and that was evident on the Agweek Corn and Soybean Tour in South Dakota.

Terry Schultz is the president of Mustang Seeds, with headquarters in Madison, and he sells seed in much of the northwestern Corn Belt. He said crop conditions vary along with the different levels of dryness across the state.

“The rainfall in South Dakota has varied more than I’ve ever seen in my 30 years in my career,” he said.

Central and north central South Dakota crop areas have suffered, but even in the southeast, Yankton County had one of the driest summers on record. Meanwhile the far southeast caught some timely rains and could have a bumper crop.

Corn yields in South Dakota could range from zero to 250 bushels per acre, with high variability even within a single field. 
Michelle Rook / Agweek
Corn yields in South Dakota could range from zero to 250 bushels per acre, with high variability even within a single field. Michelle Rook / Agweek
The unevenness of the corn crop will result in a wide range of yields according to Schultz.

Newsletter signup for email alerts

“Yield could range from zero up to 250 bushels per acre,” he said.

There will also be wide swings not only within counties, but within fields. As a result, Schultz said this year’s statewide yield average will take a hit.

“I think the average corn yield in South Dakota will be down from 25% to 30%,” he predicted.

Schultz said some of that has already been evident in the early silage that was cut. However, those yields could have been down even considering how stressed the crop was with heat during pollination on top of the dryness. Schultz said farmers have told him that the stress was worse than 1976, but the crop looked much better than it did in that year. That is just a testament to the improvements that have been made in the genetics farmers are planting today, he said.

With the stress the corn crop has suffered, standability will definitely be an issue going into harvest and may force some farmers in South Dakota to take corn before soybeans.

“You know, modern day genetics, they want to put everything in the ear," Schultz said. "When we don’t have moisture, it starts pulling that out of the stalk and the plant. So, it causes anthracnose to happen and then you will see standability issues in your corn crop in those drought areas.”

The late season rains in South Dakota were too late to add substantially to corn yields, although Schultz said it may add a bit to the test weight. He said the rains were more beneficial for soybeans, at least the later maturing varieties. As a result, he thinks soybean yields will have a big range from 20 bushels per acre on early planted fields to 60 bushels per acre in isolated spots that got some of the late August moisture. He predicted the statewide yield for soybeans will be well below average.

“I’m going to say at least a third, I think it’s going to be very similar to corn,” Schultz said.

Some early maturing soybean varieties have already been harvested and Schultz said some of their early seed bean yields have been disappointing. The beans are also drying down fast just like 2020 and could be a challenge to combine before they drop below the ideal moisture level of 13%. The result may be a very quick harvest.

In the September World Agricultural Supply and Demand Estimates report, the U.S. Department of Agriculture estimated South Dakota’s corn yields at 133 bushels per acre and soybeans at 38 bushels per acre, which are both down from 2020.