Lance Gibson and Garren Benson, Iowa State University, Department of Agronomy
Revised January 2002.
For western civilization, the story of corn began in 1492 when Columbus's men discovered this new grain in Cuba. An American native, it was exported to Europe rather than being imported, as were other major grains.
Like most early history, there is some uncertainty as to when corn first went to Europe. Some say it went back with Columbus to Spain, while others report that it was not returned to Spain until the second visit of Columbus.
The word "corn" has many different meanings depending on what country you are in. Corn in the United States is also called maize or Indian corn. In some countries, corn means the leading crop grown in a certain district. Corn in England means wheat; in Scotland and Ireland, it refers to oats. Corn mentioned in the Bible probably refers to wheat or barley.
At first, corn was only a garden curiosity in Europe, but it soon began to be recognized as a valuable food crop. Within a few years, it spread throughout France, Italy, and all of southeastern Europe and northern Africa. By 1575, it was making its way into western China, and had become important in the Philippines and the East Indies.
Although corn is indigenous to the western hemisphere, its exact birthplace is far less certain. Archeological evidence of corn's early presence in the western hemisphere was identified from corn pollen grain considered to be 80,000 years old obtained from drill cores 200 feet below Mexico City. Another archeological study of the bat caves in New Mexico revealed corncobs that were 5,600 years old by radiocarbon determination. Most historians believe corn was domesticated in the Tehuacan Valley of Mexico. The original wild form has long been extinct.
Evidence suggests that cultivated corn arose through natural crossings, perhaps first with gamagrass to yield teosinte and then possibly with backcrossing of teosinte to primitive maize to produce modern races. There are numerous theories as to the ancestors of modern corn and many scientific articles and books have been written on the subject. Corn is perhaps the most completely domesticated of all field crops. Its perpetuation for centuries has depended wholly on the care of man. It could not have existed as a wild plant in its present form.
Corn is often classified as dent corn, flint corn, flour corn, popcorn, sweet corn, waxy corn, and pod corn. The remainder of this discussion will be concerned only with dent corn, which is the major type cultivated in the United States.
Corn was the most important cultivated plant in ancient times in America. Early North American expeditions show that the corn‑growing area extended from southern North Dakota and both sides of the lower St. Lawrence Valley southward to northern Argentina and Chile. It extended westward to the middle of Kansas and Nebraska, and an important lobe of the Mexican area extended northward to Arizona, New Mexico and southern Colorado. It was also an important crop in the high valleys of the Andes in South America.
The great variability of the corn plant led to the selection of numerous widely adapted varieties which hardly resembled one another. The plant may have ranged from no more than a couple of feet tall to over 20 feet. It was not like the uniform sized plant that most people know today. For the Aztecs, Mayas, Incas and various Pueblo dwellers of the southwestern United States, corn growing took precedence over all other activities.
The principal role of the corn plant during the 19th century was closely tied to the development of the Midwest. In the movement westward, corn found its major home in the woodland clearings and grasslands of Ohio, Indiana, Illinois, Iowa, and adjacent states. These were places where it had not been grown widely in prehistoric times.
As early as 1880, the United States grew over 62 million acres of corn. By 1900, this figure had reached approximately 95 million acres; by 1910, it was over 100 million acres. The highest acreage ever recorded in the United States was 111 million acres in 1917.
From the beginning of records in the 1880s, through the mid 1930s, there was no significant increase in the national average corn yield. Yields during the 1920s and 1930s were no higher than those produced as a national average in the late 1800S.
It was not until the vast technological advances in the early 1940s that corn yields started to show significant yield increases. Prior to this time, the highest U.S. average yield was recorded in 1906 at 31.7 bushels per acre. Following moderate yield increases in the 1940s and 1950s, yields shot up in the 1960s and early 1970s to a national average of 109.5 bushels per acre in 1979. In 2000, US farmers planted over 79 million acres of corn. More than 40% of the world's corn is produced in the United States.
Total acreage is now less than in earlier years, but planting has increased in the more favorable areas of the Corn Belt. Iowa is normally the leading corn producing state, followed closely by Illinois. As early as 1910, Iowa had 8.5 million acres of corn, which averaged nearly 40 bushels per acre. In 1935, Iowa had 9.7 million acres of corn, averaging 39 bushels per acre. In 1960, Iowa averaged 62 bushels per acre on nearly 12.5 million acres. In 2000, Iowa farmers averaged 145 bushels per acre on more than 12 million acres. The highest all time record corn acreage in Iowa was 14.4 million acres in 1980.
Corn and soybeans form a major base of the Iowa economy. The combination of favorable soils, weather, and management know-how for the production of these two crops is rivaled by few other places in the world.
Although few people are directly involved in the production of these major crops, many jobs are associated with this industry. Industries involved in crop processing, marketing, production of farm machinery and other farm inputs exist because of our ability to grow crops in Iowa. Massive livestock industries also depend on feed produced from Iowa soils.
During the mid 1960s, about 75 percent of the corn was fed to livestock, 13 percent was exported, and the remainder went into human food and industrial products. By 2000, the relative amount of corn fed to livestock had decreased to 60 percent, 22 percent was exported, 6 percent was used for High-Fructose Corn Sweetener, 6 percent was processed for ethanol, and 6 percent went into other products.
Between 90 and 95 percent of the crop is harvested for grain; the remaining 5 to 10 percent is grown for silage. Of the corn fed to livestock in 1960, about 40 percent went to hogs, 20 percent to poultry, 30 percent to cattle on feed and milk cows, and 10 percent to other types of livestock. By 2000, these amounts had shifted to 29 percent to cattle on feed, 29 percent to poultry, 24 percent to hogs, 16 percent to dairy cattle, and 2 percent to other types of livestock.
One reference lists over 500 different uses for corn. Corn is a component of canned corn, baby food, hominy, mush, puddings, tamales, and many more human foods.
Some industrial uses of corn include filler for plastics, packing materials, insulating materials, adhesives, chemicals, explosives, paint, paste, abrasives, dyes, insecticides, pharmaceuticals, organic acids, solvents, rayon, antifreeze, soaps, and many more.
Corn also is used as the major study plant for many academic disciplines such as genetics, physiology, soil fertility and biochemistry. It is doubtful that any other plant has been studied as extensively as has the corn plant.
A bushel of shelled corn weighs 56 pounds.
