Farming has always been an important part of the state economy of Kansas. The main crop grown in Kansas is wheat. In fact, Kansas farmers produce about 400 million bushels of wheat per year. Kansas also ranks first in the United States in grain sorghum produced, second in cropland, and third in sunflowers produced. However, farming is not the only important part of the economy of Kansas. Many parts of airplanes are made in the city of Wichita. Also, many important companies are near Kansas City, Missouri. For example, the Sprint Nextel Corporation is one of the largest telephone companies in the United States. Its main operational offices are in Overland Park, Kansas.