The pace of consumption of U.S. corn has been slowing, as evidenced by small weekly exports, smaller weekly estimates of ethanol production, declining cattle feedlot placements, and increased slaughter of dairy cows and the hog breeding herd.

The extent of rationing required in the current marketing year that has just begun, however, is still not clear since the size of the 2012 crop is not yet known, said University of Illinois agricultural economist Darrel Good.

“The average U.S. corn yield will obviously be the most important factor in determining crop size, but the magnitude of acreage harvested for grain will also influence crop size,” Good said.

Good said that the likely magnitude of harvested acreage starts with the magnitude of planted acres.

The USDA’s National Agricultural Statistics Service (NASS) June Acreage report estimated corn acreage planted for all purposes this year at 96.4 million acres.

“History suggests the final acreage estimate will deviate, at least slightly, from this estimate,” Good said. “For example, in the previous 10 years, the final estimate of planted acres deviated by as little as 37,000 to as much as 1.345 million acres from the June estimate.”

The positive deviations (four) averaged 293,000 acres and the negative deviations (six) averaged 650,000 acres.

The recently released USDA Farm Service Agency (FSA) report of planted acreage of corn in 2012 by those participating in government programs has been used to judge the potential change in the NASS estimate of planted acreage this year. That report showed planted acreage by program participants at 93 million, or 96.5 percent, of the NASS June estimate.

“Some have suggested this report points to an increase in the NASS estimate of planted acreage,” Good said.

“However, in the previous five years, the ratio of FSA acreage to the NASS final estimate averaged 97 percent in a range of 96.7 to 97.5 percent. The ratio based on the June estimate this year is slightly smaller than that of the final ratio of the previous five years.  If anything, then, the lower ratio points to the potential for a slight reduction in the NASS final estimate of planted acreage rather than an increase,” he said.