Strong thunderstorms rolled through Iowa on the opening morning of the Iowa State Fair, putting the weather front and center. While the storms may not have been what fairgoers wanted to see, the broader weather pattern could be arriving at a good time for Iowa crops.
El Niño is helping establish an active weather pattern across the Corn Belt. DTN meteorologist John Baranick says the pattern was evident in June, relaxed somewhat during July, and has returned in August. That comes as corn and soybeans move through important grain and pod-filling stages, although the active pattern also brings an increased risk for severe weather.
For Iowa soybeans, the timing of that moisture could be especially important. August is a critical month for pod fill, and adequate rainfall helps plants continue moving sugars and nutrients into developing beans. Baranick says the current pattern could continue providing opportunities for rain through much of the remainder of the month.
Rainfall has not been evenly distributed across the entire Corn Belt. The primary storm track has generally stretched from Nebraska through the Ohio Valley, putting Iowa near the heart of the active pattern. Farther north, portions of the Dakotas, Minnesota and Wisconsin have dealt with drought during the summer, but Baranick says there is potential for some of that moisture to eventually push farther north.
Soybeans aren’t the only crop that could benefit from keeping the rain around. Corn pollination is largely complete across the region, shifting attention to how well those kernels fill.
Continued moisture during grain fill can help plants maintain development and add weight to those kernels as the crop moves toward maturity. Baranick says he has not heard widespread reports suggesting pollination problems were a major issue across the Corn Belt this season.
There are still plenty of variables between now and harvest, and an active storm pattern isn’t without risk. As Iowa saw with thunderstorms on the opening day of the State Fair, beneficial rainfall can come with severe weather attached.
But if the active El Niño pattern holds through the remainder of August, it could provide timely moisture for Iowa soybeans during pod fill and help corn add kernel weight as both crops work toward the finish line.
