Rich Keller
Rich Keller

We’re into another year, but the biggest topic of interest continues to be the drought that we saw during most of 2012 in major ag production areas of the U.S.

Whenever we track topics read the most on our website (www.AgProfessional.com), we see that drought articles continue to receive a high click open rate—although anything about fertilizer is continuously a high interest topic year after year and season after season.

The interest in the climate, what happened to cause the drought, will the drought repeat, will the soil moisture recharge by spring and what can be done to assure a good crop in 2013 with the moisture available are all hot topics. I heard and saw the interest firsthand at the end of 2012 during the University of Missouri Crop Management Conference for growers and ag retailers.

The university and Kevin Bradley, Ph.D., associate professor and state Extension weed scientist, who was in charge of organizing the conference, included specific drought topics. There were references to the drought and how that might affect 2013 in nearly every presentation from ones about weeds and insects to soil health.

Some reports suggest that the epicenter of the drought in 2012 was in Missouri, and that parts of the state continued to be some of the driest in the nation as of the end of 2012. Pat Guinan, Ph.D., Extension assistant professor and state climatologist, said, “2012 was the warmest year on record dating back to 1895” for Missouri. It was an “incredibly warm spring and summer.”

He explained that until May 1, the state was looking fairly good for moisture—no big problems—but May through November was the driest period since 1953. Everything combined for a rapid drop into drought, including unusually low atmospheric moisture content and high temperatures.

“The sun is the driver for evaporation,” Guinan said. Solar radiation caused exceptional evaporation in 2012 with Missouri having three cloudy days in May and June, whereas in a more normal year there would be 20 cloudy days.

Guinan had the same message as has been heard throughout most of the Corn Belt. “It is highly unlikely that we’ll get the moisture needed this winter to get out of this drought in 2013.”

Of general interest at the Missouri conference was a presentation by Michael Stambaugh, Ph.D., research assistant professor of forestry at the University of Missouri, who specializes in dendrochronology, which is the scientific method of dating based on tree rings.

The University of Missouri tree ring lab has weather data based on tree rings for the past 1,000 years. Most of this dating has come from trees that have been buried for hundreds and thousands of years and were recently uncovered along river beds. Carbon dating and matching trees of overlapping years of growth allows identifying trees thousands of years old. One oak tree in Missouri was determined to be 13,870 years old, and well-preserved 23,000 year-old oaks are common in the U.S.

Related to drought, Stambaugh said, “There is a 20-year dominant cycle in drought” as observed through the 1,000-year data of tree-ring study.

And drought can be much more than one or two years. Long-term decade droughts have occurred where the precipitation levels ranged from severely low to an outlier normal year. The last long-term drought, according to tree rings in the Missouri region of the country, occurred from 1909 to 1938—the Dust Bowl years. The longest drought period in the past 1,000 years was from 1148 to 1208, Stambaugh said.

Are we headed into one of those long-term drought periods? No one knows, but it is something in the back of the mind of climatologists and others that study weather patterns.