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Worst drought of century yet to comeBy Jennifer Carrico
In the mid-1950s, the Midwest experienced the strongest La Nina weather pattern in history, which caused tornados, floods and drought. That was replaced by the La Nina weather pattern experienced in the U.S. for the past two years, which has caused extreme weather as well. Iowa State University Extension Climatologist Elwynn Taylor said this weather pattern is the cause of the severe drought experienced over the past two years in parts of the U.S. This drought continues to cause problems for farmers in the Midwest. The average rooting depth for crops is about five feet and tiles have taken off any extra moisture that the soil would normally hold. Taylor said that the holding capacity in that five feet of soil is only the top 10 inches and then the excess water will be removed via the tile. "In 2011, the rain quit in July. The crops did okay because of the subsoil moisture, but that was gone by the time we harvested. Winter rain and snow wasn't enough to help, thus making worse drought conditions," he said. This year roots went down further than normal to seek water--some as deep as eight feet. "We currently need at least 18 inches of moisture to replace what we are lacking," said Taylor. "We normally get about 10 inches of moisture from October to May. If we get 12 inches, the tiles will be running again." According to Taylor, there were 24 years between the past two droughts. Usually there are 12 years between droughts, but the worst droughts have been every 89 years. "If weather keeps doing what it has been doing over the past 800 years, you can mark every 89 years as being the worst drought of the century, which means the next drought in that cycle will be in 2025," he said. Weather patterns that cause extremes mean farmers need to be serious about risk management according to Taylor. "Too much inconsistency in weather can also lead to the need for risk management to protect their investments," he said. Jennifer Carrico can be reached by phone at 515-833-2120, or by email at jcarrico@hpj.com. Date: 12/03/2012
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