Crop conditions vary across the Midwest

Kent Thiesse
If you poll corn and soybean producers across the Corn Belt regarding the condition of the 2021 crop, you will probably get a variety of responses.

If you poll corn and soybean producers across the Corn Belt regarding the condition of the 2021 crop, you will probably get a variety of responses.

Much of the central and eastern portions of the region have been getting some adequate rainfall, with some locations having excess amounts. However, many areas in the western and northern Corn Belt continue to deal with intensifying drought conditions.

Some welcome rainfall on June 26 helped alleviate the extremely dry conditions in portions of south central and southeast Minnesota.

Widespread rainfall extended across the very dry areas of the southern third of Minnesota on Saturday, June 26, with many areas of south central and southeast Minnesota reporting 1 to 2.5 inches of much needed rainfall, with some isolated locations east of Mankato receiving 3 to 5 inches of rain.

However, the rainfall amounts were highly variable, as many portions of southwest Minnesota received less than half an inch. For example, the University of Minnesota Research Center at Waseca received 1.5 inches of rainfall, while the U of M Research Center at Lamberton received only .28 inches. Many portions of drought-stricken west central and central Minnesota received very little rainfall this past weekend.

Drought conditions have continued to intensify during the month of June in the western one-third of the U.S. and in the Northern Plains and Midwest States. Drought conditions have become extremely severe in much of North Dakota and portions of South Dakota.

Severe drought conditions will likely spread into additional areas of the Dakotas, as well as adjoining areas of western and southern Minnesota, northern Iowa and Northern Nebraska. The severe drought conditions are affecting row crops, educing potential small grain yields and limiting pasture and hay production for livestock producers.

Areas that received limited rainfall this past weekend will get some temporary relief, but this will not alleviate the expanding drought concerns.

The hot, dry weather conditions throughout most of June in the Upper Midwest and Northern Plains states have brought comparisons to drought years such as 2012, 1988, 1976, and even 1934 and 1936. According to the state climatology office in Minnesota, many locations across the state were reporting June rainfall amounts in the bottom five years of the past 100 plus years.

A stalled frontal boundary brought widespread, heavy rain (3 to 10-plus inches) and flash flooding to parts of the lower Midwest. The excess moisture led to a general one-category improvement to drought conditions as short-term rainfall deficits decreased and streamflow and soil moisture improved. In the Upper Midwest, which mostly missed out on the heaviest rain, drought remains a concern.

Several locations in southwest and west central Minnesota were on track for the driest June on record, surpassing the previous records that in many cases were set in 1988. The U.S. Drought Monitor on June 22 showed that 75% of Minnesota was in a moderate to severe drought, with only portions of southeast and northern Minnesota escaping the drought designation.  

The most severe impacts from drought in corn occur from about 10 days prior to tasseling and pollination until about two weeks following. Much of the corn in the northern and western Corn Belt will be entering that critical stage in the next seven to ten days, which makes receiving beneficial rainfall, such as occurred this past weekend in portions of south central Minnesota, extremely important.

There can be some yield loss in drought stressed corn earlier in the growing period as well; however, it is usually not as significant if adequate rainfall is received prior to tasseling and silking. Soybeans tend to have a much wider window to withstand drought stress than corn. Drought stress in soybeans becomes much more critical as the plants approach the pod setting and seed filling stage in late July and early August.

Many farmers have wondered how the corn and soybean crop has been hanging on with the extremely hot and dry weather throughout most of June. It was likely a combination of early planting and excellent early season growing conditions, which allowed for very good root development in most corn and soybeans.

The stored soil moisture levels were above normal in many locations of southern and western Minnesota and adjoining areas of northern Iowa prior to planting this spring, which has helped corn and soybeans sustain during the dry conditions.

For generations, the standard measure for corn growth was “knee-high by July 4th,” which meant that the corn plant should be able to produce a crop for that year. Of course, most farmers a couple of generations ago had far different corn hybrids and much lower yield goals for their corn than do the farmers in 2021.

In today’s corn production, “waist-high” or higher corn by July 4th is more typical, which has resulted in some very good corn yields in most areas of the Upper Midwest in recent years. It would be difficult to get exceptional corn yields in the region in 2021, if corn is only “knee-high” or smaller on July 4th.

In much of Minnesota and Iowa, as well as adjoining areas of Nebraska, South Dakota and Wisconsin, the 2021 growing season started out earlier than normal, with most corn planted in the last half of April and first week of May.  Most corn in southern Minnesota and northern Iowa that was planted by early-May will likely well exceed “waist-high” by July 4th.

Some of the corn planted in April in areas with favorable growing conditions will likely approach or exceed “shoulder-high” by July 4th, which has not occurred in most parts of the region since 2017. Likely, some corn in the region will begin tasseling and pollinating during the first 10 days of July. Corn in areas that have been experiencing severe drought may lag further behind this development.

Corn and soybean development in most areas of southern Minnesota and northern Iowa continues to be ahead of normal in late June, due to earlier than normal planting dates and above average temperatures in June.

The accumulation of growing degree units (GDU’s) is one measurement of crop development. The total GDU accumulation at the U of M Southern Minnesota Research Center from May 1 through June 23 totaled 860 GDU’s, which is about 18% ahead of normal and compares to a GDU accumulation of 786 in 2020 and only 633 on the same date in 2019. In most areas of southern Minnesota and northern Iowa, the 2021 GDU accumulation in late June is probably at the highest level since the drought year of 2012.

Based on the June 21 weekly USDA crop progress report, 50% of the corn crop and 53% of the soybean crop in Minnesota was rated “good-to-excellent," which compares to near 80% “good-to-excellent” ratings in late June of 2020. Iowa’s “good-to-excellent” corn ratings on June 21 were at 57%, which is also well below similar ratings in 2020.

In drought-stricken North Dakota and South Dakota, the corn “good-to-excellent” ratings were only 39% and 34% respectively, with “poor-to very poor” corn ratings near 20% in both states. On the other hand, corn ratings that were “good-to-excellent” were at 83% in Nebraska, 79% in Wisconsin, 70% in Indiana, and 66% in Illinois.

Nationally, 65% of the U.S. corn crop and 60% of the U.S. soybean crop was rated “good-to-excellent on June 21, which had been declining in recent weeks. This compares to only 72% for corn and 70% for soybeans on approximately the same date in 2020. Only 6% of the U.S. corn crop and 5% of the U.S. soybean crop was rated “poor-to-very poor” as of June 21.

Emergency haying and grazing of CRP acres

As drought conditions have intensified in many areas of the U.S., USDA has been adding counties that are eligible for “emergency haying and grazing” of land enrolled in the Conservation Reserve Program (CRP). As of June 24, USDA has listed over 1,000 counties as eligible for the haying and grazing provision, including several counties in the Upper Midwest that have been added in recent weeks.

The eligible counties are updated on a weekly basis by USDA, based on U.S. Drought Monitor conditions and reports from local Farm Service Agency (FSA) offices. The haying and grazing of CRP acres do carry a number of restrictions, and CRP contract holders must make a request for emergency having and grazing through their local FSA office. Details on “CRP Emergency Haying and Grazing” program, as well as a list of eligible counties, are available via the FSA website at:

Kent Thiesse

Thiesse is a Farm Management Analyst and Vice President of MinnStar Bank