PRINTMU scientists work to solve corn crisis
Researchers are hoping the crop's past can protect its future
Photo courtesy of BRADFORD RESEARCH AND EXTENSION CENTER
Tim Reinbott plants a cover crop in the fall head of corn at the Bradford Research and Extension Center. Reinbott, and other American farmers like him, seeded more acres into corn than the nation has seen since 1937.
June 14, 2012 | 12:00 a.m. CST
Tim Reinbott, superintendent at MU’s Bradford Research Farm, passes by after row of tomatoes and peppers until he reaches his experimental sweet corn patch. Reinbott is a solid, heavy-footed man, but once he hits the corn field, he moves single-mindedly through the rows at a breathtaking pace. He tears off ears, pulls down husks and urges visitors to bite into the “Ruby Queen” and “Kandy Corn.” Before anyone can finish tasting one variety, he hands over another until discarded cobs pile up on the ground. Throughout this energetic display, he extols the genetic virtues of each ear and waxes poetic about the gene variations that make the kernels so sweet and tender.
Reinbott, like many Americans, loves corn. There might be few images more representative of Americana than a family chowing down on fresh corn on the cob in the sticky summer heat as butter drips off each of their fingers.
Experts predict that our food production must double by 2050. Scientists are working to get ...
But this kind of corn — the kind that exemplifies the American summer, the kind that sends Reinbott into a sampling frenzy — amounts to a fraction of the corn that fuels this country and just a sliver of the corn Reinbott plants at the Bradford Research Farm.
His two-acre sweet corn patch is dwarfed by the 250 acres of field corn planted for research. On a national level, field corn covered 96 million acres this year, enough to fill the entire state of Montana with a couple million acres left over. In comparison, the national sweet corn acreage hovers above 600,000 acres yearly, not enough to fill Long Island.
Field corn, the corn our nation is actually obsessed with, doesn’t even taste good. It’s left to dry in the fields well into October, until the brown stalks are shriveled and the kernels are hard. The result is a chalky dry seed — a far cry from sweet corn’s juicy kernels.
Unassuming as it might be, field corn has become an agricultural giant, second only to soybeans in its dominance of the food industry. Roughly 12 percent of U.S. corn crop ends up in our food. Cows, pigs and chickens love it. Since the corn surpluses of the 1950s, farmers have filled their diets with the dry, starchy kernels and produced the tender, fatty meat Americans have come to expect and desire.
Federal mandates now require that our cars come to love it, too. Last year, 40 percent of the nation’s field corn was fed into ethanol plants, six of which operate in Missouri. The byproduct of the ethanol process, a fibrous mash, goes to feedlots and hog pens where producers supplement livestock feed and, at times, replace the expensive corn ration.
What livestock and cars don’t use is slipped into more items than can be listed, including sweeteners, glue, diapers and pills. The rest goes abroad. Last year, the U.S. shipped millions of tons of corn out of the country, mostly to Mexico, Japan and China. Billions of dollars flowed back.
Corn has become an agricultural essential, and with good reason. Filled with sugar and energy, each kernel is nutritionally sound.
A lot is riding on those kernels today. Global and domestic demand is high and rising. The world’s population is ballooning. Asia requires more corn every year, the ethanol industry already eats up nearly half the nation’s corn production, and the American meat industry is structured around corn-fed animals.
But like all crops, corn is vulnerable to the vagaries of nature. A shifting climate and troubling limitations in corn’s modern genetic makeup are revealing the dangers of a heavy reliance on those little yellow seeds. The future of their production keeps a lot of people up at night.
Take Dr. Sherry Flint-Garcia and her colleague Dr. Mel Oliver, two USDA plant scientists who work at MU. They think we can build a better corn. Actually they, along with many agricultural experts, think we have to improve corn.
Flint-Garcia believes all the careful genetic selection that led to modern corn varieties limited corn’s potential and is now threatening its future success. By continually selecting for certain genes with the sole focus of greater production, valuable variation in other traits in corn’s genetic makeup was lost. It’s now difficult to alter major aspects of corn because breeders threw out variations of the most important genes centuries ago.
Unfortunately, the growing world population and shifting climate now require that we do just that. With the prevailing prediction that our food production must double by 2050 to feed the rising population, it is essential for scientists to get more nutrition out of each ear of corn without increasing its size or required acreage. But a kernel’s nutritional power is dependent on its size.
At the same time, most scientists believe global warming could make weather extremes such as drought and scorching temperatures a regular phenomenon for farmers. It’s already happening. A 2005 study from the National Center for Atmospheric Research found that drought incidence doubled between the 1970s and the early 2000s. Modern corn’s genes are not equipped to deal with a limited water supply.
David Grant and his father, James, grow corn and soybeans on their farm just east of Columbia. This year, Grant put approximately 600 acres into corn, but a historically dry spring has been tough on his crop so far. As he watches his parched corn roll its leaves up in the dry sun to conserve the little moisture it still has, drought-tolerant corn varieties start to sound like a pretty important development. Grant estimates local farmers lost up to a third of their normal yields to excessive heat and too little rain last year.
The complications a warming climate poses for modern corn are no distant danger for Grant. “We’re living it right now,” he says. “It’s the driest May I’ve ever seen.”
Oliver has studied drought effects on crops since the 1970s. He’s seen what a lack of water can do. In the 1980s, he recalls, 90 percent of crop loss insurance claims listed drought as the cause.
As the population grows and the planet warms, critical water reservoirs are slowly running dry. The Ogallala Aquifer, a vast underground lake that stretches from South Dakota to Texas, has shrunk by 10 percent since 1950. It’s critical, Oliver stresses, for us to find a corn variety that produces maximum yields on far less water.
Scientists such as Flint-Garcia and Oliver are left with a quandary. But part of the answer might lurk 10,000 years in the past in south-central Mexico, home of the ancient Teosinte plant.
Corn didn’t start out as a global, high-demand commodity. In fact, its distant ancestor, Teosinte, isn’t even recognizable as corn. It’s a weedy grass. But perched elusively atop its grassy stalks, narrow, brown kernels grow one on top of the other to form a single strand of seeds that became the world’s first corn.
In a small 50-by-150-foot plot back at Bradford Research Farm, Dr. Bill Wiebold, an MU plant science professor, grows Teosinte, along with dozens of other plant varieties that represent the evolutionary steps from the ancient Mexican plant to our modern field corn. He includes missteps, too: a mutated variety called “Lazy” lacks any resistance to gravity; its stalks and leaves flop uselessly toward the ground. Reinbott says Wiebold calls this microcosm of agricultural history “The Gene Zoo.”
In the 1920s, inspired by the success of hybrid animal crosses, scientists began crossing different varieties of corn that had evolved naturally from Teosinte. The genetic tinkering paid off. Scientists produced hybrids that were smaller but more efficient. The tall, bushy plants were streamlined to encourage them to put all their energy into their fruit.
This watershed event in agricultural history is shown clearly in annual statistics published by the USDA’s National Agricultural Statistics Service. Throughout the first half of the 20th-century, annual corn production held steady approximately 2 billion bushels. But beginning in the 1950s, the totals began to rise steadily and sharply. Farmers can now produce as much as 13 billion bushels a year on the same, and often less, acreage than their early 20th century counterparts.
Urbanization of America changed the landscape for many crops but not corn. Although American acres devoted to urban development quadrupled between 1945 and 2007, cropland acreage dropped by 46.2 million acres in that same period. Field corn has held strong, consistently maintaining its Montana-sized acreage decade after decade. Corn became king. But, like many monarchs in history, it’s been bred back into its own family so often, it’s now unhealthily inbred.
So Flint-Garcia has turned to Teosinte and the early corn varieties called landraces that developed from it. She tries to separate nutritional capacity from seed size by looking for ancient production genes that didn’t rely on seed size. They might not be agricultural superstars, but Teosinte and the landraces have one thing going for them: loads of genetic variation.
Oliver has taken a slightly different road. Modern corn is so genetically limited that his search for useful genes has shifted focus. He now looks for gene variations that allow different grass species’ root systems to survive dehydration. Certain dryland grass species have a lush variety of genes that allow them to revive after long spells without water. Grass could hold the answer to a major agricultural conundrum.
Such searches are an obsession for farmers and food scientists. Already, major U.S. seed companies have been working to select for drought-friendly, high-producing corn plants — with limited success. In fields from South Dakota to Texas, Monsanto, the world’s leading agricultural producer of genetically engineered seeds, is testing the first seed genetically modified to be drought-tolerant.
Universities, too, are devoting much time and money to improving corn yields, especially under drought. Back at Bradford Research Farm, the university spent $1.5 million to make sure some of Reinbott’s test crops didn’t see much rain this spring. Two brand-new drought simulators, essentially mobile greenhouses that run on rails through the fields, allow researchers to decide how much rain the test varieties can receive and when.
An early spring sent Reinbott and many American farmers into the fields early this year. They emptied bag after bag of seed into their planters and seeded more acres into corn than the nation has seen since 1937.
In the tiny spot of land devoted to The Gene Zoo, Reinbott pushed a couple dozen Teosinte seeds deep into the ground. He won’t ever see the plant produce kernels, because Teosinte needs the equal daylight and nighttime hours of equatorial Mexico to flower. But deep inside the plant’s ancient grassy stalks, its DNA might have some much-needed answers for modern corn.
