Dryness has been lingering in South Dakota for the last several weeks. The month of May was near average for temperature, and even a little on the cool side for the Eastern region. But now that temperatures have soared into the nineties and above, in combination with some wind, drought conditions have rapidly taken over Northern South Dakota.
Impact on Agriculture
It could be argued that some of our issues started with a warm fall, and late frost, and some early warmth this year. This depleted soil moisture reserves in pastures, winter wheat and alfalfa fields. Production in these commodities has declined substantially and will be difficult, if impossible, to recover yet this growing season. Significant losses have been reported over the last one to two weeks in these crops. Many Central and Northern area farmers are cutting winter wheat for hay. Alfalfa has had one cutting in some areas, where others are not cutting at all.
As a result of reductions in pasture and forage availability, livestock producers are making the tough decisions to sell cattle. Sale barns across the Region have had large increases in activity as the drought stresses their feed reserves and their bottom line.
U.S. Drought Monitor
The U.S. Drought Monitor expanded drought Regions over the last couple of weeks. As of June 6, fifty percent of the state is in drought, as defined by D1 or worse on the map (Figure 1). Eleven percent of the state is now in D2, or Severe Drought, according to the map. Severe drought can be described as approximately a one in twenty year event, comparing current conditions to the historical average for this time of year.
Much of the D2 region has had less than fifty percent of average rainfall in the last 30 to 60 days. Some areas near Mobridge and along the Missouri River have fared even worse, measuring just 25 percent or less over that same period. Typically, most areas receive about three inches a month of rain in both May and June. The current drought areas have reported less than an inch of many of those areas since May 1.
Pest & Disease Considerations
Along with the current drought situation, insect pests in some crops are becoming a concern. One typical arthropod pest is the two-spotted spider mite, which is often observed foraging in soybean during drought conditions.
Plant disease is often not an issue during dry times in crops, since most diseases flourish during wet and cool periods. Some weeds will be harder to control, as the hot and dry conditions can mean poor activation of herbicides. It may already be noticed that some pre-emerge herbicides were not as effective as expected, and some post-emerge herbicide may be needed.
Stay tuned to iGrow and the Pest & Crop Newsletter for updates on these topics during the growing season.