The worst drought in decades and accompanying heat slashed Iowa's corn and soybean yields, but Kossuth County retained its standing as the leading corn producer for 62 years.
U.S. Department of Agriculture data show farmers in the north central Iowa county harvested 52.8 million bushels of corn and 10.3 million bushels of soybeans. Kossuth, in north-central Iowa, is the largest county in the state by land area and has the most harvested acres of corn and soybeans.
The extreme temperatures and drought last year slashed corn yields dramatically across much of the state. Palo Alto and Clay were the only counties that produced corn yields above 170 bushels per acre.
The five highest yielding counties were in the northwest district. Osceola, Emmet and Pocahontas counties joined Clay and Palo Alto at the top.
The average corn yield in east-central Iowa — which includes Linn, Johnson and surrounding counties — dropped by 21.8 percent, to 134.7 bushels per acre, in 2012 from 172.3 bushels per acre in 2011.
Linn County corn farmers averaged 124.2 bushels per acre last year, down from 169.1 bushels per acre in 2011. Johnson County producers recorded an average corn yield of 132.4 bushels per acre in 2012, down sharply from 171.9 bushels per acre the previous year.
Kossuth, Sioux, Tama and Plymouth were the four largest soybean-producing counties last year. Only eight counties recorded recorded an average yield as high or higher than in 2011.
The average soybean yield in east-central Iowa fell by 15 percent, to 49.8 bushels per acre, in 2012 from 58.6 bushels per acre in 2011.
Linn County soybean farmers averaged 45.6 bushels per acre last year, down from 57.1 bushels per acre in 2011. Johnson County producers recorded an average soybean yield of 46.9 bushels per acre in 2012, down from 55.2 bushels per acre the previous year.
Looking ahead, the USDA at its annual Outlook Forum on Friday forecast U.S. corn supplies will more than triple, following a record large harvest in the fall, as strong competition from Brazil and Argentina limit U.S. exports and ethanol production stays flat.
The USDA projected a corn crop of 14.53 billion bushels, up 35 percent from the drought-slashed crop of 2012, assuming normal weather and yields. The agency estimated prices for corn will tumble by 28 percent to $4.80 a bushel.
The U.S. soybean crop is projected at a record 3.4 billion bushels this year, a 13 percent increase from 2012's drought-hit crop, according to the USDA. With the larger crop, soybean use was forecast to rise by 3 percent.