A U.S. Department of Agriculture report shows Iowa once again led the nation in corn production last year with a harvest of 172 bushels per acre. The U.S.D.A. pegs Iowa’s final corn yield at 2.356 billion bushels, an increase over 2010, but down from the record 2.42 billion bushels harvested in 2009.

The 172 bushels per acre figure tops the 2010 harvest of 165 bushels per acre. Nationally, the U.S.D.A. has set the yield at 147.2 bushels per acre, which is 5.6 bushels below the 2010 harvest. Iowa’s soybean harvest for 2011 was 50.5 bushels per acre, down slightly from 51 bushels per acre in 2010.