"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 the likely magnitude of harvested acreage starts with
the magnitude of planted acres. The USDA's National Agricultural
Statistics Service June Acreage report estimated corn acreage
planted for all purposes this year at 96.4 million acres.
"History suggests that 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 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 that 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.
Good said acreage of corn harvested for grain in a given year is
equal to planted acreage minus acreage harvested for silage minus
non-harvested acreage. Acreage harvested for silage has declined
over time. Acreage harvested for silage averaged about 9.2 million
acres in the 1970s and about 7.6 million acres in the 1980s. That
acreage has been relatively stable since 1990, averaging just under
6.1 million acres and in a range of 5.3 to 7.1 million acres.
"Acreage harvested for silage, however, tends to spike in years
of dry weather like that of 2012," Good said. "Compared to the
previous year, for example, silage acreage increased by 1.3 million
acres in 1980, 2.3 million acres in 1988 and just over 1 million
acres in 2002. This 'spike' pattern was not observed in 1983 or
1995, however, when harvested acreage of silage was less than in the
previous year," he said.
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In the case of non-harvested acreage, Good reported an increase
from the previous year of 780,000 acres that occurred in 1980,
460,000 in 1988, 258,000 in 1995 and 1.65 million in 2002. The
outlier in the pattern of an increase in acreage not harvested for
grain in recent dry years was 1983. The pattern that year may have
been influenced by the 21.6-million-acre year-over-year decline in
planted acreage in response to government programs aimed at reducing
the corn surplus, according to Good.
So what about harvested acreage of corn in 2012?
"We are anticipating that due to the severity of this year's
drought, the difference between planted acreage and acreage
harvested for grain will be at least as large as in 1980, 1988 and
2002," Good said. "Differences in those years averaged 10 million
acres, in a range of 9.47 (million) to 11.1 million acres. If
planted acreage was also slightly less than the NASS June estimate,
that experience points to acreage harvested for grain of about 86
million, nearly 1.4 million less than the June NASS estimate," he
said.
Under this acreage scenario, Good said a national average corn
yield near the August forecast of 123.4 bushels would result in a
crop near 10.6 billion bushels.
"If the average yield is also 4 to 5 bushels lower than the
August forecast, as we suspect, the crop may be near 10.2 billion
bushels, almost 600 million bushels less than the NASS August
forecast," Good said. "A crop of that size would require a
year-over-year decline in consumption of U.S. corn of nearly 1.8
billion bushels, or about 14 percent.
"Corn prices would likely have to remain high for an extended
period in order to motivate such a large decline in consumption,"
Good said. "The USDA's Sept. 12 Crop Production report will provide
an important update on the likely magnitude of harvested acreage,
yield and production, and bring the rationing question into clearer
focus," he said.
[Text from file received
from the University
of Illinois College of Agricultural, Consumer and Environmental
Sciences] |