Illinois measures about 400 miles from its northern border to its southernmost tip. Temperatures generally vary by 10 to 12 degrees from one end of the state to the other. Cold, fairly dry winters and warm, humid summers with ample rainfall allow the land to support many kinds of crops and livestock. Much of Illinois is comprised of fertile flat loess, left behind by glaciers and wind millions of years ago. About 89 percent of the state's cropland is considered prime farmland, ranking the state third nationally in total prime farmland acreage.
Prime farmland is important because it provides an environmentally sound base for crop production.
The central three-fourths of the state are especially well suited for growing crops, while hilly areas in the northwest and south provide excellent pasture for livestock. Although Illinois' food and fiber industry employs nearly 1 million people, there are only 76,000 farm operators, down from 164,000 in 1959. During the same time period, the average farm size more than doubled as sophisticated technology made many aspects of the industry less labor-intensive. Illinois farmers are generally more than 50 years old. About 39 percent hold jobs off the farm and consider farming their secondary occupation.