More Wet and Cool Weather Likely Coming; Here’s What to Do
Remember earlier this year when there was concern about drought in some areas?
That’s pretty much busted. Last night’s cloud buster in central Iowa that dropped between 4 and 7 inches has put the final spear in any drought concerns for 2015. Predictions made earlier this year of ample rainfall via an active El Niño are taking hold.
The increase in strength in El Niño this summer is also evident in states like South Dakota. "The July outlook indicates increased likelihood of cooler and wetter conditions throughout South Dakota this July," said Laura Edwards, South Dakota State University (SDSU) Extension climate field specialist in an SDSU iGrow release last Friday. "These temperature and precipitation projections strongly reflect a summertime El Niño pattern over North America."
So what’s to come? In central states including South Dakota, Edwards sees cooler than median temperatures are favored in the month ahead.
Besides El Niño, the lower temperature outlook is also a response to the wet soils and ample rainfall that has fallen in this region over the last several weeks. That tends to reduce high temperatures in the summer season.
El Niño is 90% likely to continue into fall, and 85% likely to continue or intensify into winter, adds Dennis Todey, SDSU Extension climate specialist and South Dakota state climatologist, in a recent update from the NOAA Climate Prediction Center.
So what does this mean?
Less heat stress than average is predicted, particularly when combined with ample moisture patterns. Crops will use less water under this scenario.
Unfortunately, this also means wheat disease issues, such as stripe rust. Weeds love this weather, too.
"Growers may also be more concerned about weeds, as the recent wet conditions have made some fieldwork difficult for pesticide application," she says. "A few warm, dry days are all a weed needs to grow quickly, and frequent scouting is suggested."
It also means your corn may need more nitrogen.
Peter Scharf, University of Missouri Extension soil specialist, says 80,000 central U.S. acres on average received 16 inches of rainfall from April through June from 1900 to 1980. That’s now grown to around 200,000 acres annually.
“When you have more than 16 inches of rain from April through June, you run a high risk of N deficiency,” says Scharf.
Even if your corn is growing too tall to sidedress N, one way to salvage the situation is through a late-season rescue N treatment.
“Overall, there is a good yield response to rescue N,” says Scharf.
That’s true for corn even at the tasseling phase.
In 2010, for example, a 57-bushel-per-acre response resulted in corn under high N stress at tasseling. Aerial photos can enable farmers to evaluate large areas quickly for N loss, says Scharf.