2021 DTN Digital Yield Tour - Day 3

Drought Trims Minnesota Yields, While Iowa and Wisconsin See Strong Crops, Tour Finds

Strong corn yields in Iowa and Wisconsin, shown here by dark green shading in Gro Intelligence's real-time yield maps, fall as you head north and west into Minnesota, where drought conditions have persisted most of the summer. (Map courtesy of Gro Intelligence)

ROCKVILLE, Md. (DTN) -- Midsummer moisture saved the season and will produce solid corn and soybean crops from Iowa and Wisconsin this year, but persistent drought has trimmed the top end off Minnesota yields.

That's the upshot from Day Three of the 2021 DTN Digital Yield Tour, powered by Gro Intelligence. Now in its fourth year, the tour is an in-depth look at how this year's corn and soybean crops are progressing using Gro's real-time yield maps, which are generated with satellite imagery, rainfall data, temperature maps and other public data. Unlike static estimates, Gro's yield projections update daily on a county and state level, so the numbers at publication time may be slightly different than what you find on the Gro website.

On Wednesday, Aug. 11, Gro's yield models expect Iowa corn to average 199 bushels per acre (bpa), up 21 bpa from last year. Soybeans in the state are expected to log an average yield of 57.4 bpa, up 4.4 bpa from last year. Likewise, Wisconsin's projected statewide corn yield of 178.5 bpa is up 4.5 bpa from last year and could surpass the 2016 record of 178 bpa. Wisconsin soybean yields are expected to have a strong, but not record-setting, showing at 50.5 bpa, on par with last year.

In contrast, Gro's models suggest Minnesota's average corn yield could come in at 180.8 bpa, down 12 bpa from last year. The state's average soybean yield is sitting at 48.1 bpa, about a bushel below last year.

To see Gro's yield models and explore the county-level detail for each state, navigate here:

-- Iowa: https://app.gro-intelligence.com/…

-- Minnesota: https://app.gro-intelligence.com/…

-- Wisconsin: https://app.gro-intelligence.com/…

Dry conditions on and off through the season will likely keep Iowa from hitting yield records, but overall, the state got enough timely rains to produce a solid crop, noted DTN Ag Meteorologist John Baranick.

"Occasional rains have done well to keep moisture timely for most plants since the middle of June across the south, while the northern portions of the state have been able to hang tight with less frequent rainfall," he said. The same is true of Wisconsin, which saw a fairly stark reversal of fortunes in June as well, Baranick added. "It was not looking good as June turned hot and the rains were infrequent," he said. "But late in the month and through July, the switch sort of flipped, and rains returned to the state."

But Minnesota proved to be the transition state, stuck between persistent, damaging drought in the Northern Plains and the moisture-fed Eastern Corn Belt, Baranick said. "Minnesota has been in a weird and rough spot all season long," he explained. "Weather conditions mirrored a lot of what was going on in the Dakotas where heat and periods of only isolated showers worsened drought conditions through July. Occasionally, the southern half of the state was able to squeak out some good rainfall events, and that was especially true in late July and early August, which brought some timely rains."


-- Corn: 199 bpa, up 21 bpa from last year.

-- Soybeans: 57.4 bpa, up 4.4 bpa from last year

It wasn't a perfect growing season for Iowa by a long shot, after a rapid planting pace ran headlong into some cold snaps in May. "A few frosty mornings likely caused some replanting in the northeast," Baranick recalled. "And drought has been in and out of the state all season long, but most consistent across the North."

But timely rainfalls kept crops on a solid footing, including welcomed moisture recently, in the first weeks of August. As a result, the state's current normalized difference vegetation index (NDVI) map, which measures relative lushness (green) or dryness (brown) compared to average conditions, shows a mostly white coloration across the state, which represents average moisture. See the map here: https://app.gro-intelligence.com/…. Pockets of brown appear across the northern half of the state, especially in the northwestern corner, but the southeast section of the state is mostly green.

That's where Lindsay Greiner grows corn and soybeans in the rolling hills of southeast Iowa near Keota, where he typically battles drought. This year, though, ample and timely rains kept even his sandy soils from drying out and his crops a healthy green, Greiner said.

Gro's corn yield model shows strong corn yields distributed almost uniformly in the top three-quarters of the state. There, yields range mostly from the 190s into the low-200s, with a cluster of counties east of Iowa City reaching into the 210s. Currently, the far east-central county of Scott boasts the highest average corn yield of 217 bpa. Yields are lower in the bottom quarter of the state, sitting mostly in the 170s and 180s, and bottoming out at 168.7 bpa in southernmost Davis County.

In Keokuk County, where Greiner farms, Gro estimates an average corn yield of 191.6 bpa. On his best ground, Greiner expects corn yields to average well over 200 bpa. On rougher ground, he predicts yields close to 200 bpa.

For soybeans, a string of counties with especially strong yields run along the eastern border, as well as pockets in northwest, north-central and west-central Iowa. There, yields range from the upper 50s into the low-60s; elsewhere, county averages sit solidly in the 50s. The best soybeans so far appear to be in far northwest Sioux County, at 63.1 bpa on average. The state's south-central tier of counties see the lowest average yields, down to 48.7 bpa in Davis County.

Greiner expects his soybean yields to average in the mid- to high-50s, much like the Gro estimate of 57.3 bpa for his county. Overall, based on the reports he gets from around the state as an Iowa Soybean Association board member, he said the yield tour's estimates for Iowa seem solid to him.

"The numbers sound realistic to me," Greiner added. "Usually, things aren't as bad as you think they are or not as good as you think."


-- Corn: 180.8 bpa, down 11.2 bpa from last year.

-- Soybeans: 48.1 bpa, down 1 bpa from last year.

The irony of Minnesota's now-middling crop season is how well it started, noted DTN's Baranick. "Early in the crop year, conditions were favorable for planting in April and early May," he recalled. "But as the calendar turned to June, it got very hot and very dry as well."

Timely rains in June and July saved many crop regions, particularly in southern Minnesota, from far worse conditions, but northwest counties of the state remain in deeply droughty straits. "It has been a tough year in that northwest corner of the state," Baranick said. "Very little rainfall has been noted, and the area is seemingly missed by potential events that have moved through elsewhere."

That dynamic is clear on the NDVI map, with much of the state nearing average moisture conditions, except for a swatch running northwest from Minneapolis up through Grand Forks and deepening into drought north of Fargo. There, Gro's Drought Index, which runs from 0 to 5, puts the northwest corner of the state near 4.5. You can see the Drought Index here: https://app.gro-intelligence.com/….

Gro's corn yield models unsurprisingly register the state's worst average county yields in the northern third of the state, with the northwest county of Polk sitting at 89.4 bpa. Yields improve in the southern half of the state, where average yields climb through the 170s and 180s. The highest yields are found in the southeast corner, topping out at 200 bpa in southernmost Mower County.

For soybeans, the same dynamic is at play in the state, with yields improving reliably by gradations as you move from the northern half of the state down toward the higher-yielding southeast corner. The lowest average yield drops to 32 bpa in northwest Pennington County, while the highest clocks in at 58 bpa in far southwestern Wabasha County.

But even in that southern region, significant rain is needed to hold on to this yield potential, notes Mark Nowak, who farms near Wells, Minnesota. In late July, he believes his corn and soybeans could have made 220 bpa and over 50 bpa, respectively. But now, with less than half an inch of rain since July 12, those yields are gone forever.

"We're going backward every day now," Nowak said. "I walk into my fields almost every day. I'm seeing (corn ear) tip back, which is the fastest way to lose yield because it's out of moisture. I squeeze pods and they are not filling as they should."

Gro's models project average corn yields of 190.6 bpa in Faribault County where Nowak farms. The models peg soybean yields at 55.8 bpa. Nowak believes both estimates are too high, unless more than an inch of rain falls within the next several days that is not in the forecast.

"If you look at the crop from the road or sky, it looks pretty darn good yet, but we're not getting the moisture to finish it," he said. See Nowak touring his crop fields and evaluating yield for the tour in this video here: https://www.dtnpf.com/….


-- Corn: 178.5 bpa, up about 5 bpa from last year.

-- Soybeans: 50.5 bpa, even with last year.

A dry April and May led to an early planting surge, but cold weather around Mother's Day forced some replanting in Wisconsin, Baranick recalled. Drought crept across the state, and early June was hot and dry, but rains returned in July. One large weather event was close to being classified as a derecho, and although there were reports of wind damage, the rainfall was beneficial and timely for corn and soybeans, he noted.

"That continued into August, and rainfall across the state over the last week has been on the order of 2-5 inches across the primary growing regions," Baranick said, adding that it's excellent for filling crops. "After the poor start to the growing season, it is amazing how quickly the turnaround was for the state.

"There remains one small section of moderate drought across the southern quarter of the state, but much of that is likely to disappear on the drought monitor that comes out Thursday."

The result of recent rainfall is an NDVI map for Wisconsin that includes small patches of both brown and green tones, which show how lush or dry a crop is compared to average. However, much of the state is white, indicating average moisture. You can view that map here: https://app.gro-intelligence.com/….

Wisconsin's corn yield map shows the most potential in the state's south, where yields range from 180 bpa to lower 190s. Lafayette County, along the Illinois border, boasts the highest average yield, with Gro's models pegging it at 195.6 bpa.

There's a pocket of lower corn yields in Adams and Marquette County, but most of the lowest yields are found in the state's northern reaches. The lowest county yield of 126.4 bpa was in Ashland County along Lake Superior.

For soybeans, the strongest yields are also concentrated to the southwest and northeast of Madison, with models indicating yields in a range of 52 bpa to 60 bpa. Lafayette County again grabs top honors, with a county average yield of 63.75 bpa. The lowest average yield is 32.9 bpa in Oneida County.

On Thursday, Aug. 12, the tour will explore the Eastern Corn Belt, specifically Indiana, Illinois and Ohio. It will wrap up on Friday, Aug. 13, with a final look at Gro's overall national yield predictions for the 2021 corn and soybean crops.

See the tour's analysis of crops in Nebraska and the Dakotas on Day One here: https://www.dtnpf.com/… and it's Day Two examination of Missouri and Kansas here: https://www.dtnpf.com/….

To learn more about the DTN Digital Yield Tour and Gro Intelligence, visit the tour's Spotlight page here: https://spotlights.dtnpf.com/… and Gro Intelligence here: https://gro-intelligence.com/….

Email your own observations as the tour progresses this week to katie.dehlinger@dtn.com, Emily.unglesbee@dtn.com and matt.wilde@dtn.com.