Market attention continues to focus on the potential size of the U.S. corn and soybean crops. Acreage totals look to remain uncertain for the rest of the year. Any adjustments in the next World Agricultural Supply and Demand Estimates report may not reflect the changes facing both crops this year.

U.S. average yields appear set to be less in the upcoming World Agricultural Supply and Demand Estimates report because severe delays in planting indicate reduced yield potential. Expectations for the U.S. average corn and soybean yields this year continued to deteriorate during recent weeks as planting delays dragged on across much of the Corn Belt. In particular states in the eastern Corn Belt dealt with extreme moisture and massive delays this year.

Yield potential decreases for corn planted after the second or third week of May, all other conditions equal. Even though progress accelerated this past week on drier weather, corn planting after May 25 came in at a more-than-average percentage. Based on the U.S. Department of Agriculture’s weekly Crop Progress report, an estimated 51 percent of the corn acreage in the 18 major corn-producing states went in the ground after May 25. That compares to the average of 16.8 percent from 1986 through 2018.

Late-planted acres typically remain isolated in specific areas of the country. While most of the very late planting this year occurred in eastern corn-producing states, a substantial amount of late-planted acreage occurred in almost every Corn Belt state. The USDA’s weekly ratings of corn conditions due out this week in the Crop Conditions report should provide an initial indication of the 2019 crop. That conditions report might be one of the worst on record.

Data available since 1986 indicate that as of week 23 of the year – June 9 this year – an average of 67 percent of the crop was rated in good or excellent condition at the end of week 23. That number excludes 1995 when ratings were not yet available due to extremely late planting.

The five-worst years for good and excellent ratings excluding 1995 show the comparison to this year.

  • 1992 at 42 percent
  • 1988 at 47 percent
  • 1996 at 50 percent
  • 1990 at 52 percent
  • 1993 at 57 percent

Late-planted corn acreage including 1995 came in at well more than average in each of those years except for 1992 and 1988. Crop-condition ratings usually decrease as the growing season progresses. Early-season ratings don’t supply an unbiased indication of the final U.S. average yield. Even so the upcoming rating, along with severe planting conditions, should keep yield expectations poor.

If one includes 1995 with the five years mentioned with the worst of good and excellent ratings, the U.S. average corn yield came in at more than trend only in 1992 – at 11 bushels more – and 1990 at 2 bushels more. The average yield across all six years totaled 9 bushels less than trend. While the upcoming World Agricultural Supply and Demand Estimates report may not decrease the corn yield much, an expectation this year for corn yield at or less than trend appears reasonable.

Soybean planting lagged at well less than average pace this year as well. As of the June 3 Crop Progress report, 39 percent of the crop in the 18 major soybean-producing states was planted. An expectation of substantial planting progress during the next few weeks is in place. Based on the USDA’s weekly Crop Progress report, an estimated 72 percent of the soybean acreage in the 18 major soybean-producing states went in the ground after May 25. That amount sits at well more than the 39.2 percent average from 1986 through 2018.

Field trials in Illinois indicate yield losses of more than 10 percent after May 20, with increasing levels as planting moves into June. Planting after June 10 led to almost a 20 percent loss expectation for soybean yields. While that seems drastic, actual national data on soybean yields rarely falls outside a range of 3 bushels from trend.

Due to the later planting of soybeans this year, the first crop-condition ratings for soybeans looks to be out in the next two weeks – depending on the percentage of the crop emerged. Crop-condition ratings for soybeans tend to decline more than corn as the growing season advances. Like corn early-season ratings don’t provide a reliable indicator of the final U.S. average yield.

Lesser yield expectations for corn and soybeans seem plausible. By factoring in late planting, a conservative yield estimate for corn of about 170 bushels per acre appears reasonable, 4.5 bushels less than the current USDA projection.

Uncertainty regarding acreage levels for corn will linger, but acreage reduction in the range of 7 million to 12 million acres produces a corn crop 1.7 million to 2.2 billion bushels smaller than currently projected by the USDA.

For soybeans an average yield of 47.8 bushels fits current conditions – that’s 1.7 bushels less than current USDA projections. If one assumes 2 million additional soybean acres due to switching, soybean production comes in 150 million bushels less than forecast by the USDA. The World Agricultural Supply and Demand Estimates report June 11 should provide the first indication from the USDA about the size of both crops this year. The June 28 acreage report will be the next major indicator.

Todd Hubbs is an agricultural economist with the University of Illinois-College of Agricultural, Consumer and Environmental Sciences. Visit aces.illinois.edu for more information.