Doane economists traveled the Corn Belt between July 25 and August 2 assessing the corn and soybean crops. This is Doane's annual effort to determine the production potential ahead of USDA’s August 11 Crop Production report. We have been conducting the tour for 28 years and have found the information helpful in making mid-summer yield and production estimates.

Doane’s corn yield estimate for the August Crop Production report is 157.5 bushels per acre for a record-high production total of 13.221 billion bushels, up 6 percent from 2010.

Methodology and observations

This season’s crop tour meant traveling nearly 3,000 miles across the heart of the Corn Belt. We checked corn fields for ear counts and ear development in addition to condition ratings for fields observed along the route. We also checked soybean fields for blooming and podding, but did not collect objective yield data for soybeans since August is the key month for determining soybean yields. This is the same methodology we have employed in the past.

This year’s crop tour yielded a wide range of crop conditions and included a few surprises in the Western Corn Belt. Corn yield prospects are generally more favorable in the western Corn Belt where the crop in general was planted on time and has since received normal to above normal precipitation.

Crop maturity varied widely along the eastern route in the Eastern Corn Belt. Corn was just tasseling and silking in southern Illinois, eastern and northern Indiana and much of northwestern Ohio. We didn’t find many abandoned fields, though. And while ponding is evident, in areas outside the low spots, stands were good and plant populations high. However, after the wet spring and early summer, these areas have since turned extremely dry. Heat and dryness have hit the crop just as water needs are peaking. The heat and dryness are clearly taking a toll on the crop. Some yield potential has been lost. Without moisture relief soon, yields in these areas are at risk of severe losses. On the other hand, favorable weather in August would stabilize yields.

Summary details

Doane’s national corn yield estimate is 157.5 bushels per acre for a production total of 13.221 billion bushels, up 6 percent from a year ago. Although recent trade estimates range from 152 to 156, we don’t expect USDA’s August estimate to come in that low.

Record or near record plant and ear populations will likely support a USDA yield in the 158 to 159 bushel range. Similar to 2010, though, the risk is that as lower ear weights are factored into the calculation as the crop matures, the national average yield is likely to come down. Lower ear weights in 2010 accounted for most of the 900 million bushel decline in the production estimate from August to the final yield in January.

Doane’s 157.5 bushel yield does imply a below trend ear weight, but a repeat of last season’s ear weight would pull the national yield down to the low 150s. Also, our production estimate assumes harvested acreage at 83.968 million acres, down from USDA’s June estimate at 84.888 million.

We expect an adjustment lower reflecting the excessive rainfall in the northwestern Corn Belt this spring, river flooding as well as losses in the drought areas of the southern Plains. USDA’s August estimate provides a benchmark for production and yield.

On average USDA’s August estimate is about 70 million bushels below the final. In absolute terms, the error or difference from August to the final production estimate is nearly 400 million bushels. Last season’s 900 million bushel downward adjustment from August to January is more the exception rather than the rule.