In 2004, U.S. farmers produced 11.8 billion bushels of corn (a bushel is about 35 quarts). Most of this is used to feed animals; only about 6 percent of the corn produced in the United States is used to make corn sweeteners. This small percentage, however, has made a big difference in the food supply.

According to the National Corn Growers Association,U.S. farmers plant about 90 million acres of corn each year, with less than 1 percent of that being sweet corn. The vast majority is field corn, bred for its high starch content and harvested when the kernels are hard and relatively dry. Field corn is the main ingredient in most livestock feed. It is also processed into a wide array of foods, such as breakfast cereals, salad dressings, margarines, syrups, and snacks, as well as products like baby powder, glue, soap, alcohol, medicine, and fuel ethanol.

The iconic American meal of a cheeseburger, fries, and shake includes several corn-based ingredients: the patty (corn-fed beef), the cheese (cornstarch), the bun (high-fructose corn syrup), the ketchup (high-fructose corn syrup and corn syrup), the fries (corn oil), and the shake (corn syrup solids and cellulose gum).

The United States is currently the number one corn-growing country in the world, with more acres devoted to corn than any other crop. In 1920, an acre cornfield yielded just 20 bushels of corn, compared to 180 bushels today. Several factors have led to both the higher yield and the greater total acreage of corn.

First, in 1930, a hybrid seed was developed that produced plants with sturdier stalks, allowing them to be grown very closely together and to resist being blown over. Then, in 1947, scientists discovered a way to convert surplus ammonium nitrate (which had been used in explosives during World War II) into a chemical fertilizer that increased soil nitrogen levels; this made it possible to grow corn from year to year without exhausting the soil. In the 1970s, a major change in the U.S. farm policy included direct payments to farmers and encouraged them to grow corn and sell it at any price; not surprisingly, this resulted in a dramatic increase in the total U.S. acreage of corn as many farmers converted their land to field corn. More recently, the federal push for corn-based ethanol production as an alternative to fossil fuels prompted farmers to convert more land to field corn.

In the 1960s and 1970s, scientists discovered how to develop a low-cost sweetener from corn known as high-fructose corn syrup. Since that time, high-fructose corn syrup and corn by-products have found their way into nearly every processed food and drink sold today. While cattle, pigs, poultry, and sheep eat about 60 percent of the corn grain that is grown each year, most of the remaining corn is processed at a wet mill, which turns it into a variety of substances. The skin of the kernel becomes vitamins and nutritional supplements; the germ is crushed for corn oils; and the rest of the kernel—the starchy endosperm—is made into acids, sugars (including high-fructose corn syrup), starches, and alcohols.


Ian Cheney & Curt Ellis

Behind America’s dollar hamburgers and 72-ounce sodas is a key ingredient that quietly fuels our fast-food nation: corn. In King Corn, recent college graduates Ian Cheney and Curt Ellis leave the east coast for rural Iowa, where they decide to grow an acre of the nation’s most powerful crop.

Alarmed by signs of America’s bulging waistlines, the filmmakers arrive in the Midwest enthusiastic about their new endeavor. For their farm-to-be, they choose a tiny town in Floyd, County, Iowa—a place that, coincidentally, both Ian and Curt’s great-grandfathers called home three generations ago. They lease an acre of land from a skeptical landlord, fill out a pile of paperwork to sign up for subsidies and discover the U.S. government will pay them 28 dollars for their acre. Ian and Curt start the spring by injecting ammonia fertilizer, which promises to increase crop production four-fold. Then it’s planting time. With a rented high-tech tractor, they set 31,000 seeds in the ground in just 18 minutes. Their corn has also been genetically modified for another yield-increasing characteristic: herbicide resistance. When the seedlings sprout from Iowa’s black dirt, Ian and Curt apply a powerful herbicide to ensure that only their corn will thrive on their acre.

By summer, their modern farm is thriving, and the Corn Belt is moving toward a record harvest of 11 billion bushels of corn. But where will all that corn go? With their crop growing head-high, Ian and Curt leave the farm to see where America’s abundance of corn ends up. As they enter America’s industrial kitchen, they are forced to confront the realities of their crop’s future. In Brooklyn, it sweetens the sodas of a diabetes-plagued neighborhood. In Colorado, it fattens the feed trough of a 100,000-head cattle feedlot. Ian and Curt are increasingly troubled by how the abundance of corn is helping to make fast food cheap and consumers sick, driving animals into confinement and farmers off the land. Animal nutritionists confirm that corn feeding can make cows sick and beef fatty, but it also lets consumers have fast food at low prices. As feedlot operator Bob Bledsoe says in King Corn, “America wants and demands cheap food.”

As Ian and Curt discover, almost everything Americans eat contains corn. High-fructose corn syrup, corn-fed meat, and corn-based processed foods are the staples of the modern diet. America’s record harvests of corn are supported by a government subsidy system that promotes corn production beyond all market demand. As Ian and Curt return to Iowa to watch their 10,000-pound harvest fill the combine’s hopper and make its way into America’s food, they realize their acre of land shouldn’t be planted in corn again—if they can help it.