This week’s extreme heat has had an overall negative impact on the state’s crops, said Laura Edwards, SDSU Extension Climate Field Specialist.
“Crops, particularly in northeastern South Dakota, are stressed due to the heat and lack of moisture,” Edwards said. “In a way the heat has helped the corn crop which has been lacking growing degree days this summer, and needed the higher temperatures for plant development. However, when the plant is developing it requires more moisture which has not been available. The lack of moisture is also impacting soybean fields.”
The new US Drought Monitor map for South Dakota reflects this condition. Moderate Drought (D1) has been introduced roughly from Brown and Spink County and east to the Minnesota border. Several stations in this area are honing in on their top 10 driest August on record.
“Many parts of the corn, soybean and sunflower growing region are suffering from dryness in the northeast,” she said. “The big change from last year was that temperatures had been below average until late August, reducing the amount of crop water use and stress. The recent heat has reintroduced the stressed conditions in these dry areas. Somewhat easing the stress has been the high dew points, which reduce some crop water use.”
Edwards said the additional heat has help push crop development along. Overall development is still behind compared to the five-year average.
“Overall crop and rangeland conditions present a good picture for South Dakota with generally fair to good crop conditions and small areas poor to very poor in this week’s USDA crop reports,” she said. “In contrast to the dry areas several stations across various parts of the west have been very wet in August leading to drought recovery.”
Edwards said several stations in the west will be in the top 10 wettest for the month of August. In particular, Lemmon has had its wettest year on record since Jan. 1. During August the U.S. Drought Monitor map has shown improving conditions over West River counties.
Cold front projected
According to the forecast, Edwards said there is a cold front projected across the state over the weekend which will bring an end to the high heat index conditions. It will bring small chances for precipitation, but then it appears things could turn dry again.
“The next best chances of rainfall may start about middle to late next week. Temperatures should remain near to above average for at least the next week or so,” she said. “But the warmth should not be as severe as this week, nor will the dew point be as high.”
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