As the end of the 2012 production season rapidly approaches, growers are asking: What is the likelihood that this year's devastating drought will be repeated in 2013?
A repeat is certainly possible, but droughts of this year's magnitude and intensity are infrequent. In fact, based on land area coverage alone, you would have to go back to 1988 to find a drought with similar national coverage, says Al Dutcher, University of Nebraska Extension state climatologist.
Thankfully, national droughts of this year's intensity materialize an average of once every 15-20 years. When multiyear droughts do occur, western areas of the U.S. Corn Belt are particularly susceptible, he says. In this area, off-season moisture is the primary driver for drought risk while in the central and eastern Corn Belt, normal off-season moisture is more than sufficient to replenish soil profiles.
UNL research has found that 70% of the moisture that falls from October through April will make its way into the soil profile. As bad as the drought was this year across the nation's midsection, the prospects for normal soil moisture recharge are higher than normal.
"Although this sounds counter intuitive, remember that in a normal year, corn and soybeans were still actively growing in September," Dutcher explains. "With corn and soybeans shutting down early, soil moisture recharge can start early, as long as the atmosphere cooperates."
When the remnants of hurricane Isaac dropping 2-5 inches of precipitation across portions of Missouri, Illinois, Indiana, and Ohio, soil moisture is building there. However, Isaac offered little reprieve for the western Corn Belt.
"We'll be watching precipitation patterns through November before predicting the potential drought risk for 2013," he adds.
Dutcher says, "It is important to remember that when we quantify drought, we are looking at two types of drought. Agricultural droughts respond quickly to short-term precipitation events, while hydrological droughts extend longer than six months and can still be relevant event when agricultural conditions are optimum.
"As long as your specific region has received normal moisture during the fall and spring, your risk of an agricultural drought during the growing season is entirely dependent on the mean jet stream pattern. Just because the fall is dry, doesn't mean that you are going to experience drought conditions the next growing season. A wet spring can make up for fall precipitation deficits. What we have found here in Nebraska is that our more significant drought risks occur when moisture during the fall/spring recharge period falls below 80% of normal."