Iowa recorded a (realized) gross farm income of $11.5 billion in 2001, the 3rd highest in the US. Nearly half of all cash receipts from marketing came from the sale of livestock and meat products; about one-fifth derived from the sale of feed grains. In 2002, Iowa ranked 1st in output of corn for grain and soybeans and third for oats.
The early settlers planted wheat. Iowa ranked 2nd in wheat production by 1870, but as the wheat belt moved farther west, the state's farmers turned to raising corn to feed their cattle and hogs. Two important 20th-century developments were the introduction in the 1920s of hybrid corn and the utilization on a massive scale during World War II of soybeans as a feed grain. Significant postwar trends included the rapid mechanization of farming and the decline of the farm population.
In 2002, Iowa had 92,500 farms, with an average size of 340 acres (138 hectares) per farm. This total represents a decrease of 48,000 farms since 1970, although the amount of land being farmed has only declined 0.7% to 32,600,000 acres (13,200,000 hectares) over the same period.
Nearly all of Iowa's land is tillable, and nearly than nine-tenths of it is given to farmland. Corn is grown practically everywhere; wheat is raised in the southern half of the state and in counties bordering the Mississippi and Missouri rivers.
In 2002, production of corn for grain totaled 6.27 billion bushels, valued at $4.418 billion; soybeans, 494.9 million bushels, $2.67 billion; oats, 13.3 million bushels, making Iowa the 3rd largest producer in the US; and hay, 5.64 million tons.