By Kent Thiesse
After a very wet spring and late planting season in most of the Midwest, crop conditions had begun to improve in late June and early July in many areas. However, a series of severe storms in Minnesota and other Upper Midwest states in mid-July has caused crop damage and raised further questions about crop quality for corn and soybeans.
Many portions of Minnesota and surrounding states have received nearly double the normal precipitation amount for the month of July during the first three weeks of the month alone. Some areas received 5-8 inches of rainfall or more during the week of July 14-20. Very hot and humid weather across the Upper Midwest raised dew points to extremely high levels, creating numerous thunderstorms with excessive rainfall amounts. This has resulted in drown-out damage and saturated soil conditions. Some severe storms have also featured hail and wind damage.
One resulting concern from excessive rainfall was lack of nitrogen for growing corn. Soil nitrogen losses increase substantially during heavy rainfall events. Corn plants in saturated soils have a much shallower root system and are not able to access the nitrogen that is deeper in the soil profile.
In some cases, farmers have side dressed nitrogen fertilizer; however, others have not been able to apply any supplemental nitrogen due to the continual wet field conditions. Producers should evaluate the condition of the corn crop before deciding to invest in supplemental nitrogen applications this late in the 2019 growing season.
The rain is also delaying herbicide applications to control broadleaf weeds. Most weed control management systems for corn and soybeans rely heavily on post-emergence weed control applications during the growing season — a challenge in a year like this. Continued wet field conditions have also created issues for farm operators trying to plant cover crops on prevented planted acres.
One positive about the weather trend during the first half of July was the warmer than average daytime and night-time temperatures, which has resulted in a rapid accumulation of growing degree units. The accumulation of GDU’s at the University of Southern Minnesota Research Center totaled 1,181 GDUs from May 1 through July 17, about 4 percent behind normal. This is a big improvement from early June, when GDU accumulation 20 to 25 percent behind normal.
Most of the Corn Belt dealt with some very late planting dates in 2019, as well as some cool temperatures and poor growing conditions in late May and early June. The warmer than normal temperatures have helped some of the later planted crops catch up. Some of the corn that was planted in the first half of May began to tassel and pollinate during the week of July 14-20, which is only a few days behind normal.
The U.S. and Minnesota crop ratings in the weekly USDA Crop Progress Reports have remained fairly steady in recent weeks. The July 15 weekly report indicated that 58 percent of the corn and 60 percent of the soybeans in Minnesota were rated “good” to “excellent”, while 10 percent of the corn and 7 percent of the soybeans were rated “poor” or “very poor”.
By comparison, at this same time in 2018, 77 percent of the corn and 75 percent of the soybeans in Minnesota were rated “good” to “excellent”. Nationally, 58 percent of the corn and 54 percent of the soybeans were rated “good” to “excellent” as of July 15, with most states in the eastern Corn Belt below 50 percent “good” to “excellent” for both crops. A year-ago in mid-July, USDA rated 72 percent of the corn and 69 percent of the soybeans in the nation were rated as “good” to “excellent”.
In the July 11th World Supply and Demand Report, USDA projected the 2019 U.S. average corn yield at 166 bushels per acre, and the 2019 U.S soybean yield at 48.5 bushels per acre. Many analysts are questioning the current USDA yield estimates, based on the challenging growing conditions in many areas of the U.S. this year. Final 2019 U.S. crop yields end up will depend heavily on the weather conditions in the next two months, as we approach Fall harvest.
Most analysts are also questioning USDA’s 2019 crop acreage total in the July WASDE report, which indicated 91.7 million planted acres of corn and 80 million planted acres of soybeans. There was only a reduction of 5.7 million planted acres of corn and soybeans in the U.S., as compared to the original intended planted acres in the March USDA acreage report. Grain marketing analysts are typically estimating 10-12 million prevented planted acres of corn and soybeans for 2019.
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