Corn, also known as maize (the terms are interchangeable), is one of the most important crops in the world, and is the largest crop of the Americas. Almost 700 million metric tons of this nutritious and valuable plant are harvested annually worldwide – and yet most of us know only that it was shown to the Pilgrims by the Indians and that it tastes great boiled on the cob with butter and salt. Today we’ll talk in a little more depth about where this critical crop comes from, how it is grown today, and the many uses we have for this ancient plant.
Taxonomy and Natural HistoryMaize is in the genus Poaceae, which includes perhaps as many as 1000 different species of grass. Maize is related to the common cereal plants like wheat, oats, barley, rice, etc. and the lawn and prairie grasses we are all familiar with. Genetic evidence indicates that the plant we know today as maize or corn was first domesticated in about 7000 BC, from a variety of wild grass known as teosinte. Today’s corn-on-the-cob eater, and even most farmers, wouldn’t recognize that early form of corn – the plants were much smaller and less fruitful than today’s variety. By about 1500 BC, Mesoamerican farmers had developed maize into a plant that we would recognize today, although modern varieties are still larger and more robust. In the 15th and 16th centuries, maize cultivation spread across the world as European colonization of the New World made its native plants accessible to farmers world-wide. Still, more than half of the world’s maize cultivation still takes place in the Americas, maize’s ancestral home.
Each maize fruit, known as an “ear” in common use, is actually the reproductive organ of the female plant, and is structurally analogous to ordinary flowers – but tastes much better! The maize flower is tightly wrapped in leaves, called a husk, which protects the plant from pests and harsh environmental conditions until the plant is ready to reproduce. There are a variety of breeds of maize which have different sizes and growing cycles, but the common agricultural varieties grow to about 8 feet in height. Maize grows in a wide variety of climates and soils, but is cold-intolerant, and is thus generally planted early in the year in the temperate zone. The plant also has a shallow root system and is thus somewhat dependent on external irrigation for optimum crop yield.
Maize as FoodMaize is useful in an incredible variety of food products. Corn kernels, which are actually seeds, may be ground into flour and made into flatbreads (such as tortillas) or quickbreads (i.e., muffins). The flour yield per pound is far greater than that of wheat, but it has only a fraction of the gluten; therefore its rising capability compared with that of wheat or rye bread is poor. It is thus used far more often for tortillas and other flatbreads than as conventional baking flour.
Maize kernels are also used as cereal; what is known as “popcorn” (produced when the kernels of certain varieties are subjected to high levels of dry heat, causing the starches to explode) was originally eaten as a type of “puffed” breakfast cereal. Corn meal (coarsely ground flour) is also cooked and served as a form of hot cereal such as grits or Italian polenta.Most Americans are most fond of corn either in its popped variety, or boiled, steamed or roasted and served either on the cob or stripped from the cob as a side dish. These varieties of maize are lower in starch and higher in sugar, and are known as sweetcorn.
Other Uses of Maize
Corn is an efficient plant, which grows quickly and well and produces consistently high yields; it was accordingly one of the plants of choice in the decision to produce ethanol-based fuels for internal combustion engines. This usage has increased the demand for maize in recent years, putting price pressure on the crop, and in the view of some analysts, making food prices higher. The use of biofuels as an adjunct to petroleum products seems unlikely to end or decline in the near future, and it is expected that corn production worldwide will continue to increase to compensate for the increase in demand. In addition to its use in producing ethanol, corn and corn-byproducts such as cobs and stalks are used as a heating fuel in some areas.
Maize is widely used as feed for livestock, particularly cattle, especially in the U.S. and Canada. Other uses of corn includes the manufacture of sweeteners (corn syrup, a principal ingredient in many soft drinks and other sweet foods), alcoholic beverages (i.e., bourbon and sour mash whiskey), and corn is even sometimes used in fabric or as a plastic substitute.
Maize ProductionMaize is now the most widely grown food crop on the planet; world production in 2005 was 692 million metric tons according to the UN Food and Agriculture Organization. This was up from 600 million in 2003; maize production in the U.S. accounted for just under half of that figure in both years, as the US continues to be a leader in corn production worldwide. In 2007, maize production in the U.S. increased 24%, owing to an increase in the acreage devoted to maize cultivation as well as greater yields. At the Renewable Energy Conference in October 2007, U.S. Secretary of Agriculture Mike Johanns predicted that new, more drought-tolerant varieties would increase production by another 40% in the next few years.
The soil in which maize is grown must have a high pH level in order for the niacin in the plant to be released; otherwise, the plant will have reduced nutritive value. If the soil is very acidic, it may need to be amended with ash or lime. Ancient Mesoamerican farmers used lime or potash to enrich the soil to release the niacin; when maize was first grown worldwide, farmers did not know this was a requirement and a maize-related nutritional deficiency disease, pellagra, was the result. Pellagra has essentially disappeared since the 1930s, when it was discovered that the soil used for growing corn required this enrichment.
