Fundamentally Speaking

The 2014 U.S. corn yield at 173.4 bushels per acre (bpa) is a new record surpassing the old high of 164.4 bpa back in 2009.

Depending on what time range is used this is anywhere from 7.9% to 11.5% above a trend yield.

Earlier in the year there was talk that given the superlative crop conditions as measured by the USDA along with producer comments, final corn yields this year could be more than double digits above trend similar to what was seen in other superlative growing seasons such as 2004 and 1994.

Though there will be another crop report issued early next year, for the most part the 2014 season is history with attention turning to next year.

Along these lines, the accompanying graphic shows the 10, 20, 30, and 40 year trends for corn along with the actual yields in bushels per acre.

There has been a healthy debate within the trade as to what length of time should be used in trend-line calculations.

It is often said that looking ahead into the future the more recent time periods will give a better indication as to what to expect as opposed to more distant history.

This has a great deal of importance in this issue for the disastrous 2012 corn yields along with the below par 2011 and 201 crops seem to have skewed the trend yield calculations using the more recent data.

For instance, using the 40 year trend, U.S. corn yields increase by an average of 1.81 bpa per year and the same for the 30 year trend. The 20 year trend has yields increasing by 1.85 bpa however while the 10 year trend has yields increasing by a mere 0.78 bpa per year.

As a consequence, using a 40 year trend, the prospective 2015 U.S. corn yield calculates to 162.0 bpa, the 30 year 162.1 bpa, the 20 year 162.5 bpa but the prospective ten year trend points to a yield of 156.3 bpa.

Of course the USDA has a new weather adjusted corn yield model unveiled last year that pegged the 2014 yield at 165.3 bpa and a figure close to 167.0 could be used at their February Agricultural Outlook session.

(KA)