La Nina could threaten 2016 corn, soybean crops

OREANDA-NEWS. December 09, 2015. The wet weather cycle known as El Nino could transition to a dryer La Nina in 2016, threatening serious drought conditions for the US corn and soybean harvests.

The 2015 El Nino event ranks as one of the strongest episodes to date, bringing severe storms to the US Gulf coast and the Midwest regions, according to the National Oceanic and Atmospheric Administration (NOAA).

Such severe El Nino episodes have historically transitioned into La Nina events, said United States Department of Agriculture (USDA) meteorologist Brad Rippey.

A La Nina is associated with cooler-than-normal water temperatures in the equatorial Pacific ocean, which ushers in dryer weather and higher-than-normal temperatures typically seen in the Southwest, Southeast and Central Plains regions, according to NOAA. La Nina causes contrary weather patterns when compared to El Nino, which is associated with warmer-than-normal water temperatures in the equatorial Pacific Ocean. El Nino typically increases summer rainfall in the southern portions of the US and causes milder winters in the northern regions.

Although it is too early to tell, Rippey said timing is key when determining the effects a potential La Nina could have on the US corn and soybean crops.

"There is an enhanced risk of heat and drought perhaps somewhere in the United States, but I think it's way too early to try and pinpoint a forecast on that," he said.

A transition into La Nina conditions could be delayed as NOAA warned in mid-November of El Nino peaking in late-2015 and early-2016. Rippey said if this year's El Nino lingers into next spring, it would bode well for the corn and soybean crops by bringing in needed precipitation during plantings. But too much rain could delay plantings by limiting farmers' field times. Increased precipitation during the planting and growing seasons could pressure corn and soybean prices downward because of increased crop yield potential.

If this year's El Nino collapses into a La Nina too early in the planting season, similar to what happened in 1983, it could usher in severe drought conditions during the growing season, Rippey said. US corn yields were reported at 81.1 bushels/acre in 1983-84—the lowest since 1974-75 and down by 32.1 bushels/acre from the prior season, according to the USDA. Less noticeable yield effects were realized during the last El Nino/La Nina in 1997-99, when the average corn yields were 126.7 bushels/acre and 134.4 bushels/acre, respectively, despite a severe El Nino that eventually transitioned into a La Nina.

La Nina's historical effect on corn prices also differs. In 1983-84 average farm corn prices jumped by 26pc, or more than 60?/bushel, from the prior year because of decreased supply as a result of a decrease in planted acres, according to the USDA. Conversely, the La Nina-impacted 1998-99 season, which collapsed from the 1997-98 El Nino, saw average corn prices decrease by 49?/bushel from the prior year. The 1998-99 La Nina drought was primarily contained in South America and Mexico and did not affect the US Corn Belt, Rippey said.

"Time is everything," Rippey said. "If we see El Nino collapse into La Nina at a bad time during the growing season, it could play a significant role in the outcome of 2016."