Telegraph Herald

Some concerns cropping up about La Nina Obstinate climate pattern could bring difficulties for growers and consumers

Agriculture and weather experts already are discussing whether La Nina conditions could threaten the 2008 growing season.

The La Nina designation was announced in September but if the weather patterns change at the usual rate, it could mean good news for Midwestern crop growers as the effects could diminish by summer.

La Nina is characterized by unusually cold ocean temperatures in the Equatorial Pacific, according to the National Oceanic and Atmospheric Administration. El Nino is characterized by unusually warm ocean temperatures in the Equatorial Pacific.

Bryce Anderson, Data Transmission Network of Omaha, Neb., chief ag meteorologist, said typically La Nina lasts nine months to a year, but the weather pattern could potentially last as long as two years.

For the Midwest, La Nina can lead to some very dry spring and summer conditions. The La Nina of 1988 resulted in devastating droughts. U.S. corn yields dropped by 30 percent in 1988 compared to 1987, Anderson said.

The good news for this La Nina cycle is that if it follows the average time frame, it could be nearly finished by the time crops are being planted.

Anderson said current topsoil and subsoil moisture levels in Iowa currently are significantly higher than they were at this time in 1988, which also is helpful for the upcoming year's crops.

Elwynn Taylor, a climatologist at the Iowa State University Extension Service, wrote last month that La Nina conditions are now posing a "significant risk" to U.S. corn production this year.
While some research groups assert La Nina might diminish quickly and thus pose little risk to crops, Taylor warns the United States is not in the clear yet.

"When the La Nina is in place in June and July, the risk of a below trend yield in the U.S. Corn Belt is 70 percent," Taylor's weather and crop comments state. "This risk is increased by scant subsoil moisture, the 19-year drought cycle and existence of drought in the area of South Carolina. At this time, the combined risk is a 68 percent chance of a below trend U.S. corn yield."

If a drought does occur, Anderson said there would be a tremendous impact on the volatile grain markets.

"We're in a situation right now with demand, not just for ethanol but for exports, that if there were to be a weather scare during the growing season, we could easily add another dollar to corn on the futures market,"

And that means consumers could expect to pay even more for many of their favorite food products.
By early spring, Anderson said he expects to have a better idea of whether the Midwest will be impacted by this La Nina.

"At this time, we're kind of optimistic about how things are shaping up for the Corn Belt," Anderson said.