Barring potential tropical storm rains that could impact some of the eastern Corn Belt, the Midwest is primed for good weather during the 2021 harvest season, according to Bryce Anderson, DTN Ag Meteorologist Emeritus.
“Currently, the Pacific Ocean temperatures are cooling, setting up the likelihood of a La Nina developing during the September to November season. When a La Nina occurs during the fall, conditions are usually pretty dry over much of the Plains and the western two-thirds of the Midwest,” he says.
If the hurricane season continues to push more tropical weather storm activity, the widest trajectory would impact the Southeast, catching the Appalachians, the eastern half of Ohio, Pennsylvania, and the mid-Atlantic states. “This area could see the greatest chances for rainfall, but any impact on yield would be fairly minimal due to tropical activity,” Anderson says.
The downside of a drier harvest season is the lack of soil moisture recharge, especially over the northern plains where the hot and dry weather pattern continues. “Dry soils in the Dakotas and Minnesota helped produce record heat this summer. Moisture is needed in the air to help cool temperatures, by using some of that heat energy to evaporate the moisture,” he adds.
Record-setting drought brought the heat this summer during the April through mid-August crop period. “For example, Sioux City, Iowa, saw its second driest climate ever (tied with 1936); Yankton, South Dakota, was the driest ever; and Vermilion, South Dakota, had its second driest weather on record. Even tiny Menno, South Dakota, had its third driest climate, and they have weather records going back about 100 years,” he says.
Growers in these drought areas are worried about a possible early frost. However, Anderson points out current temperature forecasts indicate it's unlikely an early frost will occur.
“The best scenario we can hope for in these dry soils is a delay in the hard freeze of the ground along with some snow cover. Snow tends to soak into a soil profile very efficiently before the ground freezes. That will help provide needed moisture headed into next spring,” he says.
The Corn Belt’s international competition to the south is also facing drought this year. “La Nina has a real high relationship to dry conditions in Argentina and southern Brazil, which could come on top of Argentina’s already terrible drought,” Anderson says. “The water levels on the Parana River are the lowest in about 50 years, which really complicates the transport of grain to ports.”
These soil moisture dryness concerns in South America could lead to spring planting issues in October and November. “And with La Nina gaining momentum by December into January, that doesn’t bode well for Argentina soil and crop moisture situation,” he adds.
Another issue that commodity traders watch is the mid-September start date of soybean planting in the Mato Grosso area of Brazil. “Then on the backside of a potentially late soybean harvest season would be a late planting of safrinha corn (second crop)—putting that crop into a possibly stressful situation, depending on when the rainy season ends and the dry season begins,” Anderson explains.
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