BLOOMINGTON, Ill. (AP) - Along with Chicago's soaring skyline and Abraham Lincoln's prairie roots, Illinois is best known for routinely producing one of the nation's top yields of corn and soybeans.
Some soil scientists say the state should be as well known for what's behind those yields: rich, black dirt that is unmatched for fertility in the U.S. and equaled by only three other places in the world.
"God didn't make many places as good as this," said Robert McLeese, state soil scientist with the U.S. Department of Agriculture's Natural Resources Conservation Service office in Champaign.
Only patches of farmland in Argentina, the southern Ukraine and along the Yellow River in China match the fertile ground that covers much of the northern half of Illinois, particularly a high-yielding band through the state's midsection, state soil experts say.
From Bloomington to tiny Bethany near the banks of Lake Shelbyville, city and chamber of commerce promotions tout the rare earth the way Florida plugs sunshine. Web sites across the region boast the richest farmland in the nation, if not the world.
Those claims are greeted like a late-summer drought across the border in Iowa, which historically ranks with Illinois atop rankings of corn and soybean production.
"Have they not been to Iowa? We'd have to disagree for sure," said Holly Coppola, spokeswoman for the Iowa Farm Bureau.
Both states trace their rich farmland to glaciers that covered much of the region before they began retreating about 12,000 years ago.
Soil scientists say the glaciers left prime farmland through much of Illinois north of Interstate 70, which cuts through the south-central part of the state. They say the richest soil is in a swath that runs east from around Springfield to the Indiana border.
"If it isn't the richest farmland in the world, it's a least some of the richest. … It's not hype, it's true," said Jeff Squibb, a spokesman for the Illinois Department of Agriculture.
Iowa farm officials, without meaning to take anything away from the soil that helps produce Illinois' roughly $7 billion annual grain crop, nevertheless take exception to such talk.
"There's absolutely no doubt in my mind that Illinois and Iowa both are both blessed with above-average soils from a fertility standpoint," said Mark Salvadore, a research analyst with the Iowa Farm Bureau.
As evidence, he cited the neighboring states' neck-and-neck yield averages in 2004. Illinois averaged just over 50 bushels an acre for soybeans, compared with 49 bushels in Iowa, while Iowa's corn harvest averaged 181 bushels an acre, topping the 180-bushel average in Illinois.