Opinions about likely summer weather in the Corn Belt center on the El Nino/La Nina Southern Oscillation (ENSO). The Climate Prediction Center forecasts that the winter La Nina is transitioning to neutral conditions. “Historically, such a transition has usually been associated with corn yields near trend value, although deviations in both directions have occurred,” said Good. Others are suggesting a transition to an El Nino and increased chances of an above-trend yield in 2012.

U.S. corn plantings are expected to increase by 2 to 3 million acres in 2012. It has been argued that the increase will occur in lower-yielding areas and therefore prove to be a drag on the U.S. average yield.

Good thinks the yield implication of increased acreage is likely to be extremely small. “First,” he said, “some of the increase in corn acreage may occur in the higher yielding areas of the eastern Corn Belt since acreage there in 2011 was below the recent peak of 2007. Second, a 2 to 3 percent increase in acreage has the potential to impact the U.S. average yield only marginally even if all the increase was in low-yielding areas.”

While the 2012 yield debate will continue well into the growing season, the most logical expectation is for an average yield near the long-term trend. The trend yield for 2012 is just less than 160 bushels per acre. The USDA’s early forecast for 2012 is for a yield of 164 bushels.

With harvested acreage projected at 87 million acres, a 4 to 5 bushel difference in the U.S. average corn yield represents a difference of 350 to 435 million bushels in crop size. Prospects of an average yield near 160 bushels would suggest that new-crop corn prices are probably low enough, while prospects for a yield of 164 bushels or higher would likely push prices marginally lower.

More detailed analysis will be provided in upcoming posts at farmdocdaily.