Soil moisture recharge unlikely by 2013
Drought-stricken Midwestern areas aren’t likely to have fully recharged soils by the time the 2013 planting season rolls around, says Elwynn Taylor, Iowa State University (ISU) climatologist.
Taylor told those attending the recent ISU Integrated Crop Management Conference the typical soil profile requires 16 inches of water to be fully recharged. Typically, each foot of soil will hold 2 inches of water. In 2012, roots went down as deep as 8 feet to extract water. Thus, a fully depleted soil profile would require 16 inches for a full water recharge.
“Do not count a full recovery of soil moisture before planting time,” he says. Even if parts of the Midwest receive lots of snowfall, remember it typically takes a foot of snow to equal an inch of water.
Parts of Indiana and Illinois caught September rains that were the remnants of Hurricane Isaac. Other areas, though, haven’t been as fortunate. The most recent U.S. Drought Monitor shows a stage 4 (most severe on the rating scale) drought in the central Great Plains of South Dakota, Nebraska, Kansas, and Oklahoma, with neighboring regions showing degrees of drought.
This dry set-up going into 2013 doesn’t bode well for returning to USDA’s trend line corn yields of around 162 bushels per acre. Although it likely be better than this year’s 122 bushels per acre yield, 2013 is likely to be the fourth year below trendline yields, says Taylor. This was keyed by the second strongest La Nina weather event ever in 2010. This follows an anomaly of above-trendline yields of the six previous years (2004 to 2009).
“That is rare,” he says. “Out of the past 100 years, we never had more than six years in a row of above-trendline yields.”
Taylor thinks the past few years may be ushering in a period of volatile weather—and yields. If weather patterns of the past 700 years remain constant, we may be on the end of 25 years of relative stability and entering a 19-year volatile period.
That’s not necessarily bad. Risk management tools like proper hybrid selection, crop inputs, crop insurance, and other tools has given farmers good training in dealing with volatile weather. “Now comes 25 years to use it,” says Taylor.