La Niña Seen Keeping U.S. And Argentina Dry

The U.S. Plains and Argentina, two of the world’s top grain-production areas, will remain dry for the foreseeable future due to a strong La Nińa which is likely to hang on for months, a forecaster said Jan 5.

“The southern plains dryness is of real concern. We see no sign of that changing anytime soon,” Mike Palmerino, agricultural meteorologist with Telvent DTN weather, told the Reuters Global Ags Forum, an online grain industry community.

“The next real threat to the crop is the potential for very cold weather to move into the region during the next couple of weeks,” he said. “There is the potential for widespread sub-zero readings between about January 11 to January 18.”

The arctic blast will further stress the wintering wheat and increase the likelihood of winterkill, he said.

The region has been suffering from drought conditions after an unseasonably dry autumn and early winter. The driest is the western edge of the belt, stretching from western Kansas to eastern Colorado into southwestern Nebraska.

The HRW wheat crop is seen especially vulnerable to winterkill if temperatures dip to -15 to -25 F (-26 to -32 C) wind chills and the wheat stays uninsulated and thus unprotected by the usual winter snow cover on the dormant plants, which were seeded last autumn and revive in the spring.

“The crop has been weakened by drought and is more susceptible to cold weather and high winds as it is not as well established,” Palmerino said.

State crop reports released this week show that wheat conditions have deteriorated in the leading HRW wheat states, including Kansas where wheat conditions fell to their lowest ratings posted for a December in at least 10 years.

The abnormal dryness in the Plains is a fallout from a strong La Nińa, a weather anomaly, that occurs every three to four years and characterized by cooler sea surface temperatures in the Pacific Ocean, disrupting weather patterns globally.

“The current La Nińa when you incorporate all the indices appears to be the strongest in 32 years. That La Nińa lasted throughout the following year,” Palmerino said. “I would feel comfortable at this point to say that the La Nińa could last through the U.S. 2011 growing season.”


Argentina, the world’s second- largest corn exporter and third-biggest soybean exporter, is also feeling the effects of La Nińa right now. Only minimal showers early in the growing season now suggest corn and soybean yields will be hurt.

“The driest area in Argentina so far this growing season has been in northern Buenos Aires province, averaging only 25 per cent of normal rainfall since November 1,” Palmerino said.

A large portion of Argentina’s corn and soybean belt remains deficient in rainfall, and is projected to remain so, while temperatures are likely not going to be persistently hot, Palmerino said. The Argentine corn crop is now pollinating while soybeans’ key yield-determining period is weeks ahead.

“Ultimately it may be more of a problem for beans than that for corn, with beans more moisture sensitive and corn more heat sensitive,” Palmerino said.

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