Since 1990, there has not been a strong tendency for NASS to either raise or lower the national soybean yield estimate in the October crop report. There have been 11 years that the yield was lowered by an average of 0.9 BPA, 12 years that NASS’s yield increased by an average of 1.1 BPA, and 2 years that the yield was unchanged. More recently, yield has been unchanged or higher in 8 of the last 13 years, with only minimal declines noted. However, there have been some surprising declines that have developed as crops have matured. The largest decline occurred in 2003, when both pod weights and pod counts declined in October, and continued to fall into the January Crop Report. By January, pod counts were down 5% from the September count and the average implied pod weight was 8% lighter. Crop scouts travelling through IA and IL last week reported IL pod counts down 20% from a year ago, while IA pod counts were 28% lighter than last year. The October soybean yield could be a surprise.
Looking at corn yields, there has been a stronger tendency for that national corn yield to increase. Looking back to 1990, NASS has increased it’s corn yield estimate in 15 years (56%) by an average of 2.8 BPA, and lowered the yield estimate in 9 years (33%) by an average of 2.6 BPA. There were 2 years (1998 & 2011) that the yield was unchanged, and in 2013 there was not an October crop report due to a Federal Government shutdown. The largest increase in the corn yield occurred in 2004, though conditions and weather were far different than this year. The largest decline was in 2010, when warm overnight August temps kept plants stressed, and the corn yield fell by 6.7 BPA. Crop scouts last week counted an average IA/IL ear population at 97% of last year versus NASS’s September estimate of that was at 99%, while average kernels per ear were 10% under a year ago. We doubt that a 2010 type decline occurs, but our late September field survey’s suggest that a 2-3 BPA yield decline could occur.
The October Crop Report has a number of moving pieces with regard to summer row crop production forecasts. In addition to the yield changes, NASS will draw on certified acreage data, remote sensing information, and other data sources, and make any necessary changes to acreage. But not surprisingly, changes to production forecasts are directed by changes in yield estimates. Since 1990, soybean production in October has declined by as much as 7% in 2003, and risen by as much as 10% the following year in 2004. On average, the soybean crop size can be expected to change by 2.9%, which this year would be 127 Mil Bu. In corn, the range has been a 6% increase in 2004, to a 4% decline in the years of 1993, 1995, and 2010. On average, corn production can be expected to change by 1.6%, which would be a 226 Mil Bu change this year.
