August was one of the driest in history for some areas of the U.S. — like Ohio and Indiana. The onset of flash drought may have trimmed yield potential for both corn and soybeans, and it could also result in an earlier start to harvest.
Eric Snodgrass, senior science fellow with Nutrien Ag Solutions, says it was an abrupt change from too much rain early in the season.
“All of a sudden, the Bermuda high leaves and now we start watching the Delta, the mid-South and the eastern Corn Belt go very dry,” Snodgrass says.
Those drought conditions showed up in the most recent U.S. Drought Monitor, authored by USDA meteorologist Brad Rippey.
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“We still need moisture in the southern and eastern Corn Belt into the Northeast. [We’re] also keeping a close eye on the western drought, which has come on strong this summer,” Rippey says.
Flash Drought Develops
However, some areas of the eastern Corn Belt are seeing a flash drought, which just came on in the last three weeks, according to Snodgrass.
“In fact, there’s been a three-class degradation and drought in the mid-South and along the Mississippi River down there in the Delta,” Snodgrass says.
The bull’s-eye of the drought in the eastern Corn Belt is even more obvious when you look at a climate map that ranks the precipitation according to deviation from normal.
“It starts right here where I am in east central Illinois and then moves across a big section of Indiana and gets into Ohio — but don’t forget Kentucky and Tennessee,” Snodgrass says. “During that summer time frame, were there pockets of drought developing? Yes. Where I am here, when you subtract evaporation from the precipitation total, we’re 8" off of normal.”
Extreme Heat Also Had a Role
He says the flash drought was also a result of heat in June through most of August.
“Our biggest stressor is the fact that we saw, when compared to average, an additional 25 nights where the low temperature was greater than 70°F. We just never brought the temperatures down enough at night to really allow the crop to rest. Even though it’s cool now, it wasn’t that way in June, July and most of August,” Snodgrass says.
Is It Cutting Yield?
That likely impacted back-end kernel depth, or the fill on corn. When combined with increased disease pressure, it potentially trimmed yields.
Missy Bauer, agronomist with B&M Crop Consulting, says: “When we have poor conditions — whether heavy disease pressure, a lack of nitrogen in some areas or maybe dry weather — all of those influence the finish of that crop. It can be so variable based on that. If you just do math alone and you say, ‘Well, I got 90,000 kernels in a bushel versus 60,000 kernels in a bushel’, that’s 100 bushel difference per acre.”
Rains are even more critical in August to fill out the soybeans, so both crops may be going backward from the August WASDE.
Don Roose, U.S. Commodities, says: “We had the Pro Farmer [Crop] Tour going through, and some others, coming up with a lot of disease issues out here in both corn and soybeans. So, its very realistic that we’ve seen the biggest numbers in corn and soybeans from a yield standpoint going forward.”
Snodgrass says though there are upcoming chances for rain in some of these drought areas, it may be too late for the corn and may not fill in all the holes in the soybean crop.
