The U.S. Corn Belt - the world's top grain region - is seeing another dry winter after the worst summer drought in half a century, reducing prospects for a bumper summer harvest that would help ease global food prices, crop and climate experts said.
"We are still concerned about getting the leftovers out of the way from the drought of 2012. At this time we would not anticipate a national corn yield above the trend," said Iowa State University climatologist Elwynn Taylor, who has studied crop production for decades. "Rather, we would expect a fourth consecutive year of below-trend crop, not as far below as in 2012 but still not up to par."
The 2012 drought locked two-thirds of the U.S. continental land mass in severe drought last summer, cutting production of the biggest crop, corn, by 27 percent from early season estimates.
The U.S. supplies more than half of world exports of corn, which is the top livestock feed for meat and dairy animals, the main feedstock for ethanol production, and the leading ingredient in dozens of food and industrial products from vegetable oil to sweeteners, paints and plastics. As such, its price is a key for food inflation and its supply outlook is closely watched by Federal Reserve policymakers, bankers, farm suppliers and food processors.
On Thursday, the government's weekly U.S. Drought Monitor said that 42.05 percent of the continental United States remained in severe to exceptional drought, down from 42.45 percent the previous week. Parts of the Corn Belt east of the Mississippi River and parts of the central Plains received snow over the last week, providing some much-needed moisture. But the snow did not offer much drought relief, with little improvement expected over the winter, according to the report.
Taylor and other crop specialists said continued lack of snow and rain was the biggest threat in the western Corn Belt - Minnesota and South Dakota south to Iowa, Nebraska, Missouri and Kansas. Those states produce about half the U.S. crop.
Taylor said in December it would take about 16 inches of precipitation by April 1 to recharge moisture in Corn Belt soils, up from the usual 12 inches that farmers look for over the winter.
The moisture is vital to spur adequate corn, soybean and spring wheat plant roots, which extend several feet down to tap into subsoil moisture. Persistent drought over more than a year in many areas meant plant roots drove down 8 or 9 feet last year in search of moisture, compared with the usual 5 feet.
"Most agricultural soils hold about 2 inches of water available to crops per foot of soil," Taylor said. "With most of the moisture gone that means it will take 16 inches of water soaking into the soil and in some places 18 to fully replenish it."
A Long Shot
Jim Angel, state climatologist in Illinois, said the state's conditions had improved slightly but have a long way to go before spring. Some areas of Illinois would need up to 21 inches of precipitation to catch up.
"The 2012 drought is not over yet. There are several areas of the state that are 8 to 12 inches below normal in rainfall, some places even more. You don't have to totally erase the deficits to be out of the drought but you have to come pretty close," Angel said. "In wintertime it's tough because we don't get that much precipitation. It's a long shot at this point."
Illinois saw its second hottest year on record in 2012, averaging 55.5 degrees, or 3.3 degrees above normal, and the 10th driest. The state's subsoil moisture is still rated 67 percent short to very short, according to the Illinois crop update issued this week.
Nebraska, the third largest corn producing state, has 77 percent of the state remaining in exceptional drought, according to the latest Drought Monitor.
"The concern is we just went through a 14-15 month stretch of incredibly dry weather in most locations in the state, excluding the southeast corner. For the vast majority of locations outside that area we were looking at 40 to 50 percent of annual precipitation that fell in 2012, and that does not include the exceptionally dry fall of 2011," said Al Dutcher, state climatologist for Nebraska.
To eliminate the soil moisture deficits over the next three months, Dutcher said central Nebraska needs 300 percent of normal precipitation while northeast and western Nebraska need 500 to 700 percent of normal precipitation this winter.
"One key issue for us since we are not getting a massive amount of moisture is to keep a protective snow layer across the northern and central Plains so we don't break dormancy as early as it did last year," Dutcher said. "Last year we were putting leaves on trees in early March, typically that doesn't happen until early April. That additional month of water use compounded the problem with the drought as we got into mid-summer."
Prayers for El Nino?
Scientists are hoping they will have a better indication by early February of the seasonal weather pattern, which depends on whether conditions turn to an El Nino or La Nina - global weather atmospheric anomalies based on the warming or cooling of an area of the southern Pacific Ocean that can dictate precipitation patterns in North America.
El Nino, a warming of Pacific waters, often leads to wetter weather in the U.S. Midwest. La Nina, a cooling of the waters, can have the opposite effect.
Climate experts say the El Nino/La Nina outlook is currently "neutral" based on data from the National Weather Service and other government forecasts.
"We do not have any clear signal that's telling us whether it could be wetter or drier or near normal precipitation. That's the same for temperature," said John Eise, climate services program manager for the National Weather Service. "When you're looking out that far, going out a month or three months, it depends very strongly on whether we are in an El Nino or La Nina. Right now we are between the two."
The next El Nino-La Nina outlook from the U.S. Climate Prediction Center will be released Jan. 10.
Taylor said a return of La Nina, which the U.S. experienced in 2012, could be devastating: a return of abnormally high temperatures and diminished rains.
"We can be concerned with this dryness but we could have the same setup as 2001, 2003, 2007 that followed major drought years in western Nebraska where it turned exceptionally wet in the spring, reduced irrigation demands. We still carried a high hydrological drought, but agriculturally we were at yield trend or above trend," Dutcher said.
For the moment, however, the worries remain. Freezing temperatures hitting much of the Midwest this week will prevent any moisture from permeating the soil.
"Even if we got normal precipitation through the winter that would not necessarily take care of the drought west of the Mississippi River. It's pretty tough now," Eise said.