Geography of Corn in the United States

Caitlin Dempsey

Updated:

Corn, also known as maize, is one of the most important crop grown in the United States. The country produces roughly one-third of the world’s total corn supply, underscoring its significant role in both national and global agriculture.

Corn is a versatile crop used for food, animal feed, ethanol production, and industrial products. The rise in ethanol production, particularly after the U.S. government began promoting biofuels, has expanded corn cultivation to meet the increased demand for this renewable energy source.

In 2019, 91.7 million acres of corn in 2019 were planted in the United States. This is the equivalent of 69 million football fields. For 2021, the USDA forecasts production for corn at 14.8 billion bushels, which is a 4 percent increase from 2020.

U.S. Corn Belt

While corn can be grown in nearly every state, within the United States the majority of corn grown happens in the Midwest over a swath of area known as the “corn belt.” This area includes states like Iowa, Illinois, Indiana, Nebraska, and Minnesota. Iowa and Illinois are the top two corn-producing states, contributing nearly 35% of the total U.S. corn production. 


Free weekly newsletter

Fill out your e-mail address to receive our newsletter!
Email:  

By entering your email address you agree to receive our newsletter and agree with our privacy policy.
You may unsubscribe at any time.


Why is the Midwest a heavy producer of corn?

  • Climate: Corn is a warm-season crop that requires a specific growing season. It thrives in regions with long, hot summers and sufficient rainfall. The Corn Belt, with its humid continental climate, offers these conditions in abundance. However, corn is also grown outside the Corn Belt in states like Texas, California, and even in the arid regions of the Southwest, thanks to irrigation.
  • Soil type: The quality of soil is critical for corn production. The deep, well-drained soils of the Midwest are particularly suited for corn, but different varieties of corn can adapt to other soil types across the country. For instance, hybrid varieties have been developed to grow in sandy or clay-rich soils, expanding corn production to other regions.

Map of corn cropland in the midwest

This map created by NASA from USDA data shows the extensive of corn across the Corn Belt in the Midwest. The map uses 2020 Cropland Data Layer product provided by the National Agricultural Statistics Service.

Map showing farmland that were planted with corn in 2020.  Map: NASA using USDA cropland data.
Map showing farmland that were planted with corn in 2020. Map: NASA using USDA cropland data.

Corn beyond the Corn Belt

While the Corn Belt is the epicenter of corn production, other regions of the United States also contribute to the nation’s corn supply. In the South, corn is often grown as a secondary crop alongside cotton and soybeans. In the West, states like California and Arizona use irrigation to produce corn in more arid environments. These regions often focus on specialty corn varieties, such as sweet corn for human consumption or corn used for silage in livestock feed.

Additionally, small-scale and organic corn farming is gaining traction in various parts of the country. These operations often prioritize environmental sustainability and focus on niche markets, such as non-GMO or heirloom corn varieties. Although they represent a small fraction of total production, they contribute to the diversity of corn farming practices in the United States.

Table: Corn for grain area harvested in 2020

StateArea harvested – 2020 (1,000 acres)
Alabama  320
Arkansas  605
California  60
Colorado 1,060
Delaware  176
Georgia 390
Idaho  130
Illinois  11,100
Indiana  5,250
Iowa 12,900
Kansas  5,720
Kentucky 1,380
Louisiana 485
Maryland 430
Michigan 1,990
Minnesota 7,510
Mississippi 490
Missouri 3,280
Nebraska 9,890
New York 510
North Carolina  950
North Dakota  1,780
Ohio 3,300
Oklahoma 320
Pennsylvania  1,000
South Carolina 380
South Dakota 4,500
Tennessee 825
Texas  1,810
Virginia  420
Washington  80
Wisconsin 2,970
Other States*456
United States – Total82,467
Source: Corn for Grain Area Harvested, Yield, and Production – States and United States: 2020 and Forecasted August 1, 2021, Crop Production, USDA
*Other States include Arizona, Florida, Montana, New Jersey, New Mexico, Oregon, Utah, West Virginia, and Wyoming

During the growing season, the Corn Belt leads the world in photosynthetic activity

Researchers used remote sensing data to show that no other place on Earth has as much photosynthesis as the Midwest region of the United States during the Northern Hemisphere’s growing season.

A corn field in Iowa.
A corn field in Iowa. Photo: Peter Van Metre, USGS. Public domain.

For the study, researchers analyzed data from the Global Ozone Monitoring Experiment 2 (GOME-2) on Metop-A, a European meteorological satellite.

The data showed that the corn belt extending from Ohio to Nebraska and Kansas produced peak photosynthetic activity in July at levels 40 percent greater than those observed in the Amazon.

What is corn used for?

There are three main uses for the corn supply grown in the United States.

  1. Approximately one-third is used to feed livestock, either directly or through the use of animal feed. Corn is used as the source of carbohydrates in animal feed.
  2. Almost a third of corn is converted to ethanol which is used as a gasoline additive, known as biofuel.
  3. The remaining corn crop is used within the United States and around the world in food and drink products.
A 1918 poster: "Corn - the food of the nation Serve some way every meal - appetizing, nourishing, economical".
A 1918 poster: “Corn – the food of the nation Serve some way every meal – appetizing, nourishing, economical”. Source: Library of Congress.

Corn in Iowa

99% of corn grown in Iowa is what is known as “field corn”. Field corn is primarily grown to be used in animal feed and to convert to ethanol. Only 1% of the corn grown in Iowa is “sweet corn” for human food consumption.

Corn production around the world

Corn originated in the Americas and is now a significant crop grown around the world. Maize is grown on all continents except Antarctica.

This map of corn production was produced in 2000 from statistics from the United Nations Food and Agriculture Organization.

The dark green area of the Corn Belt is seen in the Midwest. Other significant areas of corn production can be seen in parts of Central America, Subsaharan Africa, Asia, and Southern Europe.

Map showing global corn production, 2000.  Dark green areas are areas that have high corn output.  Source: NASA using data from United Nations Food and Agriculture Organization.
Map showing global corn production, 2000. Dark green areas are areas that have high corn output. Source: NASA using data from United Nations Food and Agriculture Organization.

What are Corn Mazes?

Corn mazes are paths made by cutting or plowing through the crop (maize). Often popular in the fall, corn mazes can be seen at farm-based pumpkin patches.

References

Corn is America’s largest crop in 2019. (2019, July 29). USDA. https://www.usda.gov/media/blog/2019/07/29/corn-americas-largest-crop-2019

Corn facts. (n.d.). Iowa Corn. https://www.iowacorn.org/media-page/corn-facts

Falling for corn. (2021, November 5). Landsat Image Gallery. https://landsat.visibleearth.nasa.gov/view.php?id=149035&fbclid=IwAR2uCzOdzKOMv39MlZdRC08ujIq61xA46rFJ2T8aWb3gmb3wNlYeemTS0j4

Green, T. R., Kipka, H., David, O., & McMaster, G. S. (2018). Where is the USA Corn Belt, and how is it changing?. Science of the Total Environment618, 1613-1618. https://doi.org/10.1016/j.scitotenv.2017.09.325

Riebeek, R., & Allen, J. (2010, November 25). Maize: A global crop with American roots. NASA Earth Observatory. https://earthobservatory.nasa.gov/images/47250/maize-a-global-crop-with-american-roots

Satellite shows high productivity from U.S. corn belt. (2014, March 26). NASA. https://www.nasa.gov/press/goddard/2014/march/satellite-shows-high-productivity-from-us-corn-belt/

Photo of author
About the author
Caitlin Dempsey
Caitlin Dempsey is the editor of Geography Realm and holds a master's degree in Geography from UCLA as well as a Master of Library and Information Science (MLIS) from SJSU.