WASHINGTON — U.S. 2011 corn production was forecast at 12,432,910,000 bus, down 1% from 12,497,070,000 bus forecast in September and down 13,955,000 bus from 12,446,865,000 bus in 2010. Soybean production was forecast at 3,059,987,000 bus, also down 1% from 3,085,340,000 bus in September and down 8% from 3,329,181,000 bus last year, the U.S. Department of Agriculture said in its Oct. 12 Crop Production report.

Both U.S.D.A. production numbers were below the average of pre-report trade estimates of 12,492 million bus for corn and 3,094 million bus for soybeans.

Based on Oct. 1 conditions, corn yield was forecast at 148.1 bus an acre, unchanged from September but down 4.7 bus from 152.8 bus an acre as the final 2010 average yield. Harvested area was forecast at 83.9 million acres, down 1% from 84.4 million acres in September but up 3% from 81.4 million acres in 2010.

“If realized, this will be the fourth largest production total on record for the United States,” the U.S.D.A. said. The yield average would be the lowest since 2005.

Soybean yield was forecast at 41.5 bus an acre, down 0.3 bus from 41.8 bus an acre in September and down 2 bus from 43.5 bus an acre in 2010. Harvested area was forecast at 73.7 million acres, down 147,000 acres from September and down 4% from 76.6 million acres in 2010.

The U.S.D.A. yield numbers were below the average trade forecast of 148.9 bus an acre for corn and 42 bus an acre for soybeans.

“If realized, the average yield will be the second lowest since 2003,” the U.S.D.A. said.

U.S. 2011 rice production was forecast at 186,903,000 cwts, down 2% from 190,854,000 cwts in September and down 23% from 243,104,000 cwts in 2010.

Sorghum production in 2011 was forecast at 243,800,000 bus, down 294,000 bus from 244,094,000 bus in September and down 29% from 345,395,000 bus in 2010 and the lowest since 1956, the U.S.D.A. said.