Corn expert says Iowa yields will be widely varied this fall
October 3rd, 2011 by Ric Hanson
One ag industry expert says corn yields are expected to be widely varied across Iowa this fall. Roger Elmore, a corn specialist at the Iowa State University Extension, says several factors come into play, including the July heat wave. Elmore says very warm nighttime temperatures in parts of Iowa sped up the maturity of the corn, but it may end up limiting yields. “That high night temperature…truncated the growing season, meaning, the seed fill period was less than normal, maturity was reached faster than normal, and all of that would add up to light kernels and if all of that did happen, we’ll see a lighter yield,” according to Elmore.
He says growers who tried to capitalize on higher corn prices by planting corn on the same land where they grew corn last year may be disappointed with this year’s yields. “We always expect to see a pretty significant yield difference when you’re comparing corn following corn to corn following soybeans. On average, over the years, the best data we’ve got across the state of Iowa suggests that difference is about 14 or 15-percent.”
He says that average could be as low as zero-percent or as high as 30-percent, based on the year, the weather, the environment, the hybrid and other factors. According to Elmore, Iowa farmers can plan on seeing losses if they’re planting the same crop on the same land back-to-back. He says “On average, if you’re trying to run a spreadsheet analysis on things, just calculate in a 14 or 15-percent yield reduction from corn following corn.” If stalk conditions are good, Elmore says producers should delay harvest during this dry fall weather to allow the corn to dry down in the field.