By James Langcuster
For centuries, farmers have operated largely at the mercy of nature's fickle temperament, whether this was expressed as a late freeze, a prolonged drought or a scorching temperature spike.
Now, a growing number of them are pushing back, thanks to what climate researchers have learned
about El Niño Southern Oscillation (ENSO), recurrent and normal temperature variations in a large
swath of the eastern Pacific Ocean that influence climate conditions in the U.S. Southeast.
Jesse Scott of Malvern, Ala., is among the growing number of producers pushing back against nature
using climate forecasts based on what scientists have learned about ENSO.
"I usually plant around 100 acres of dryland corn every year," Scott says, "but from 2006 to 2011,
we had really bad rain-fed corn yields."
This hard reality prompted Scott to reduce his dryland corn acreage from about 100 to 20 acres. But
after learning about climate forecasting a couple of years ago at a meeting sponsored by the
Southeast Climate Consortium and the National Institute of Food and Agriculture, Scott changed his
mind.
Based on 2012 climate forecasts, Scott planted 95 acres of corn — a decision he has never
regretted. His 2012 yields averaged 90 bushels an acre. His crop also happened to fetch a high
price, making the decision even better, he recalls.
Brandon Dillard, a regional agronomy agent with the Alabama Cooperative Extension System, compares
the progress made in climate forecasting to what happened with fertilizer adoption during the last
century. A few early forerunners like Scott bought into it, posted significant gains and, in the
process, inspired other producers to embrace forecasting.
Also, much like fertilizer adoption, the more farmers buy into it and the more scientists study and
build on what they learn, the more refined and useful climate forecasting becomes, says Dillard,
one of several Extension educators at the forefront of efforts to help farmers benefit from these
new insights.
"When we first started this, one of the goals was for farmers to use forecasting to change how they
farmed," Dillard recalls. "I initially thought this was a bit of a stretch, but we're beginning to
see this knowledge become more refined and with this refinement has come more tools and
information."
Florida's state climatologist, David Zierden, has spent much of his career helping Southeastern row
crop producers gain a better understanding of how climate forecasting can contribute to greater
farm productivity and less risk.
"We've made some progress," Zierden says, speaking at the 14th annual Wiregrass Cotton Expo, Feb.
15 in Dothan. "We're getting a handle on the predictability of seasonal rainfall and temperature.
"It's not everything we need to know, but we're making progress."
One point driven home to Zierden and other scientists in the last couple of decades is how much
drier the month of May has become.
"The message we're trying to hammer home is that May in the southeastern United States has gotten
drier," he says. "May is a critical period in the growing season when we are trying to get seed in
the ground and a stand established before the onslaught of summer dryness.
"While June rain hasn't changed that much, May rains have declined to an average of about 2 inches
— half of what was expected 25 years ago."
Scientists have gained other insights from a close study of the ENSO pattern, which, when not in a
neutral phase, is expressed either as an El Niño or La Niña phase.
Warmer surface water temperatures in the Pacific are associated with the El Niño pattern and
typically contribute to wetter- and cooler-than-normal winters and springs in the Southeast.
Cooler water surface temperatures with the La Niña effect are typically followed by winter and
spring climate patterns much warmer and drier than normal, Zierden says.
Research has demonstrated that corn and wheat yields are affected by these phases, which become
more pronounced closer to the Gulf Coast.
"Curiously, when we have El Niño — rainy or stormy winters —we actually get reduced corn yields
across the Southeast, while the warmer, drier winters and springs associated with La Niña bring
higher corn yields," Zierden says.
Climate researchers were initially stumped by these findings until follow-up discussions with
Extension specialists and agents cleared up the confusion.
"We finally figured out what was happening," Zierden says. "Given enough water, especially with
irrigation, the warmer temperatures and increased sunshine early in the season — May and April
[during La Niña] —get corn off to a good start."
On the other hand, in the cloudy, rainy conditions associated with El Niño, corn starts off slowly,
he says.
At Auburn University, Dr. Brenda Oritiz an Alabama Extension specialist and assistant professor in
the Department of Agronomy and Soils, cautions that these connections should be studied on a
county-by-county basis.
Sorting out how these patterns play out with cotton initially proved challenging. Then a series of
crop simulation models developed by researchers at the University of Florida and the University of
Georgia shed some much-needed light on the problem, Zierden says.
The models revealed that early planting dates under the neutral phase — which happen to be the
current and forecasted ENSO phase for spring and early summer 2013 — decrease the chances for low
yields and also enhance the prospects for high yields. On the other hand, late planting dates
produce exactly the opposite: an increased chance of low yields and reduced opportunities for high
yields.
"Putting all this together — and with the understanding that I'm neither an Extension specialist
nor an agronomist — I think it demonstrates that planting early, getting a stand established and
taking advantage of existing soil moisture from winter and early spring rainfall better equips the
crop to withstand the dry periods that follow in May and June," Zierden says.
Ortiz has also been at the forefront of efforts to acquaint Alabama producers with the merits of
climate forecasting. While underscoring that these techniques are no panacea, they provide farmers
with an added layer of protection, she says.
"Farmers have to understand that when we speak of climate forecasting, we're talking about
probability, not an ironclad guarantee," she says.
"On the other hand, when you think back to the serious drought from 1953 to 1954 when farmers had
little information and few, if any, tools, we're better prepared than we've ever been."
Source : aces.edu