The hills of southern Iowa bear the scars of America's push for green energy: The brown gashes where rain has washed away the soil. The polluted streams that dump fertilizer into the water supply.
Even the cemetery that disappeared like an apparition into a cornfield.
It wasn't supposed to be this way.
With the Iowa political caucuses on the horizon in 2007, presidential candidate Barack Obama made homegrown corn a centerpiece of his plan to slow global warming. And when President George W. Bush signed a law that year requiring oil companies to add billions of gallons of ethanol to their gasoline, Bush predicted it would make the country "stronger, cleaner and more secure."
But the ethanol era has proven far more damaging to the environment than politicians promised and much worse than the government admits today.
As farmers rushed to find new places to plant corn, they wiped out millions of acres of conservation land, destroyed habitat and polluted water supplies, an Associated Press investigation found.
Five million acres of land set aside for conservation — more than Yellowstone, Everglades and Yosemite National Parks combined — have vanished on Obama's watch.
Landowners filled in wetlands. They plowed into pristine prairies, releasing carbon dioxide that had been locked in the soil.
Sprayers pumped out billions of pounds of fertilizer, some of which seeped into drinking water, contaminated rivers and worsened the huge dead zone in the Gulf of Mexico where marine life can't survive.
In Indiana, for instance, farmers planted 750,000 more acres of corn last year than they did the year before the ethanol mandate was passed. More than 28,000 acres of conservation land were lost.
The consequences are so severe that environmentalists and many scientists have now rejected corn-based ethanol as bad environmental policy. But the Obama administration stands by it, highlighting its economic benefits to the farming industry.
Farmers planted 15 million more acres of corn last year than before the ethanol boom, and the effects are visible in places like south central Iowa.
The hilly, once-grassy landscape is made up of fragile soil that, unlike the earth in the rest of the state, is poorly suited for corn. Nevertheless, it has yielded to America's demand.
"They're raping the land," said Bill Alley, a member of the board of supervisors in Wayne County, which now bears little resemblance to the rolling cow pastures shown in postcards sold at a Corydon pharmacy.
All energy comes at a cost. The global warming consequences of drilling for oil and natural gas are well documented and severe, according to many experts. In an effort to reduce those harms, however, Obama's administration has allowed so-called green energy to do not-so-green things.
The government's hopeful predictions for ethanol have proven so inaccurate that scientists question whether it will ever achieve its central environmental goal: reducing greenhouse gases.
That makes the hidden costs even more significant.
"This is an ecological disaster," said Craig Cox of the Environmental Working Group, a natural ally of the president that, like others, now finds itself at odds with the White House.
The administration accepts the cost because it believes supporting corn ethanol will encourage development of cleaner, greener biofuels.
"That is what you give up if you don't recognize that renewable fuels have someplace here," EPA administrator Gina McCarthy said in a recent interview with AP. "All renewable fuels are not corn ethanol."
Still, corn supplies the overwhelming majority of ethanol in the United States, and the administration is loath to discuss the consequences.
"It just caught us completely off guard," said Doug Davenport, a Department of Agriculture official who encourages southern Iowa farmers to use conservation practices. Despite those efforts, Davenport said he was surprised at how much fragile land was turned into corn fields.
Shortly after Davenport spoke to The Associated Press, he got an email ordering him to stop talking.
"We just want to have a consistent message on the topic," an Agriculture Department spokesman in Iowa said.
That message was laid out by Agriculture Secretary Tom Vilsack, who spoke to ethanol lobbyists on Capitol Hill recently and said ethanol was good for business.
"We are committed to this industry because we understand its benefits," he said. "We understand it's about farm income. It's about stabilizing and maintaining farm income which is at record levels."
But the numbers behind the policy have become so unworkable that, for the first time, the EPA is soon expected to reduce the amount of ethanol required to be added to the gasoline supply. Meanwhile, an unusual coalition of big oil companies, environmental groups and food companies is pushing the government to go even further and reconsider the entire ethanol program.
To understand how America got to an environmental policy with such harmful environmental consequences, it's helpful to start in a field in Iowa.
Leroy Perkins, a white-haired, 66-year-old farmer in denim overalls, stands surrounded by waist-high grass and clover. He owns 91 acres like this, all hilly and erodible, that he set aside for conservation years ago.
Soon, he will have a decision to make: keep the land as it is or, like many of his neighbors, plow it down and plant corn or soybeans, the major sources of biofuel in the United States.
"I'd like to keep it in," he said. "This is what southern Iowa's for: raising grass."
For decades, the government's Conservation Reserve Program has paid people to stop farming environmentally sensitive land. Grassy fields convert carbon dioxide into oxygen, and that combats global warming. Plus, the deep root systems prevent topsoil from washing away.
A decade ago, Washington paid farmers in Wayne County about $70 an acre to leave their land idle. With corn selling for about $2 per bushel (56 pounds), farming the hilly, inferior soil was bad business.
Lately, the math has changed.
"I'm coming to the point where financially, it's not feasible," Perkins said.
The change began in 2007, when Congress passed a law requiring oil companies to blend billions of gallons of ethanol into gasoline.
Oil prices were high. Imports were rising quickly. The legislation had the strong backing of the junior senator from Illinois, the nation's second-largest corn producer.
"If we're going to get serious about investing in our energy future, we must give our family farmers and local ethanol producers a fair shot at success," Obama said then.
President Bush signed the bill that December.
It would fall on the next president to figure out how to make it work.
Writing the regulations to implement the ethanol mandate was among the administration's first environmental undertakings. But President Obama's team at the EPA was sour on it from the start.
As a way to reduce global warming, they knew corn ethanol was a dubious proposition. Corn demands fertilizer, which is made using natural gas. Ethanol factories typically burn coal or gas, both of which release carbon dioxide.
Plus, digging up grassland releases greenhouse gases.
"I don't remember anybody having great passion for this," said Bob Sussman, who served on Obama's transition team and recently retired as EPA's senior policy counsel. "I don't have a lot of personal enthusiasm for the program."
The EPA's experts determined that corn ethanol was only modestly better than gasoline when it came to carbon dioxide emissions.
Sixteen percent better, to be exact. And not in the short term. Only by 2022.
By law, though, biofuels were supposed to be at least 20-percent greener than gasoline.
From a legal standpoint, those results didn't actually matter. Congress exempted existing coal- and gas-burning ethanol plants from meeting this standard.
Still, the ethanol industry was livid and challenged the EPA estimate. The biofuel-friendly Obama administration was undermining the industry's selling point: that it was much greener than gasoline.
The EPA's conclusion was based on a model. Plug in some assumed figures — the price of corn, the number of acres planted, how much corn would grow per acre — and the model would spit out a number.
To get past 20 percent, the EPA needed to change its assumptions.
The most important assumption was the yield, a measure of how much corn could be produced on an acre of land. The higher the yield, the easier it would be for farmers to meet demand without plowing new farmland, plowing that counted against ethanol in the greenhouse gas equation.
Corn yields have inched steadily upward over the years as farms have become more efficient. The government's first ethanol model assumed that trend would continue, rising from 150 bushels per acre to about 180 by the year 2022.
Agriculture companies like Monsanto Co. and DuPont Pioneer, which stood to make millions off an ethanol boom, argued those numbers were too low. They predicted that genetically modified seeds, which they produce, would send yields skyrocketing.
Documents show the White House also suggested the EPA raise its yield assumptions.
When the final rule came out, the EPA and Agriculture officials added a new "high yield case scenario" that assumed 230 bushels per acre.
Problem was, a spike in corn prices would encourage farming marginal areas like Wayne County, which could never produce such large yields. The EPA's model assumed only a tiny increase in corn prices.
When the Obama administration finalized its policy, corn ethanol scored 21 percent better than gasoline, barely crossing the key threshold.
"You adjust a few numbers to get it where you want it, and then you call it good," said Adam Liska, assistant professor of biological systems engineering at the University of Nebraska. He supports ethanol, even with its environmental trade-offs.
The Obama administration's predictions were soon proven wrong. In September 2010, corn passed $4, on its way to about $7, where it has been most of this year.
Losing conservation land
It's impossible to calculate how much ethanol is responsible for the spike in corn prices and how much those prices led to the land changes in the Midwest.
Supporters of corn ethanol say extreme weather — dry one year, very wet the next — hurt farmers and raised prices.
But supply wasn't the only factor.
Historically, the overwhelming majority of corn in the United States has been turned into livestock feed. But in 2010, for the first time, fuel was the No. 1 use for corn in America. That was true in 2011 and 2012. Newly released Department of Agriculture data show that, this year, 43 percent of corn went to fuel and 45 percent went to livestock feed.
The more corn that goes to ethanol, the more that needs to be planted to meet other demands.
Scientists predicted that a major ethanol push would raise prices and, in turn, encourage farmers like Leroy Perkins to plow into conservation land.
In 2008, the journal Science published a study with a dire conclusion: Plowing over conservation land releases so much greenhouse gas that it takes 48 years before new plants can break even and start reducing carbon dioxide. For an ethanol policy to work, the study said, farmers could not plow into conservation land.
In response, the Department of Energy said America could meet its ethanol demand without losing any conservation land, officials said.
They would soon be proven wrong.
In the first year after the ethanol mandate, more than 2 million acres disappeared. Since Obama took office, 5 million more acres have vanished.
Agriculture officials acknowledge that conservation land has been lost, but they say the trend is reversing. When the 2013 data come out, they say the figures will show that as corn prices stabilized, farmers once again began setting aside land for conservation.
Losing conservation land was bad. But something even worse was happening.
Farmers broke ground on virgin land, the untouched terrain that represents, from an environmental standpoint, one of the country's most important assets.
The farm industry assured the government that wouldn't happen. And it would have been an easy thing for Washington to check.
But rather than insisting that farmers report whenever they plow into virgin land, the government decided on a murkier oversight method: Washington instead monitors the amount of cropland nationwide. Local trends wash away when viewed at such a distance.
Look closely at the corn boom in the northern Great Plains, however, and it's clear. Farmers are converting prairies into farmland.
The Department of Agriculture began keeping figures on virgin land only in 2012 and determined that about 38,000 acres vanished last year.
But using government satellite data — the best tool available — the AP identified a conservative estimate of 1.2 million acres of grassland in Nebraska and the Dakotas alone that have been converted to fields of corn and soybeans since 2006, the last year before the ethanol mandate was passed.
"The last five years, we've become financially solvent," said Robert Malsam, a farmer in Edmunds County, S.D., who like others in the central and eastern Dakotas has plowed into wild grassland to expand his corn crop.
In Wayne County, a gravel road once cut through a grassy field leading to a hilltop cemetery. But about two years ago, the landowners plowed over the road.
Now, visiting gravesites means walking a path through the corn.
"This is what the price of corn does," said Bill Alley from the board of supervisors. "This is what happens, right here."
Gulf dead zone
In his recent speech to ethanol lobbyists, Vilsack was unequivocal about ethanol's benefits to the air and water:
"There is no question air quality, water quality is benefiting from this industry," he said.
But the administration never actually conducted air and water studies to determine whether that's true, even though those studies were required by law.
In the Midwest, meanwhile, scientists and conservationists are sounding alarms.
Between 2005 and 2010, corn farmers increased their use of nitrogen fertilizer by more than 1 billion pounds. More recent data aren't available from the Agriculture Department, but even conservative projections suggest another billion-pound increase since then.
Nitrogen fertilizer, when it seeps into the water, is toxic. Children are especially susceptible to nitrate poisoning, which causes "blue baby" syndrome and can be deadly.
Department of Agriculture officials note that the amount of fertilizer used for all crops has remained steady for a decade, suggesting the ethanol mandate hasn't caused a fertilizer boom nationally.
But in the Midwest, corn is the dominant crop, and officials say the increase in fertilizer use — driven by the increase in corn planting — is having an effect.
The Des Moines Water Works, for instance, has faced high nitrate levels for many years in the Des Moines and Raccoon Rivers, which supply drinking water to 500,000 people. Typically, when pollution is too high in one river, workers draw from the other.
"This year, unfortunately the nitrate levels in both rivers were so high that it created an impossibility for us," said Bill Stowe, the water service's general manager.
For three months this summer, workers kept huge machines running around the clock, trying to keep up with the demand for clean water.
In neighboring Minnesota, a government report this year found that significantly reducing the high levels of nitrates from the state's water would require huge changes in farming practices at a cost of roughly $1 billion a year.
The nitrates travel down rivers and into the Gulf of Mexico, where they boost the growth of enormous algae fields. When the algae die, the decomposition consumes oxygen, leaving behind a zone where aquatic life cannot survive.
This year, the dead zone covered 5,800 square miles of sea floor, about the size of Connecticut.
Larry McKinney, the executive director of the Harte Institute at Texas A&M University-Corpus Christi, says the ethanol mandate worsened the dead zone.
"The government is mandating ethanol use," he said, "and it is unfortunately coming at the expense of the Gulf of Mexico."
Obama administration officials know the ethanol mandate hasn't lived up to its billing.
The next-generation biofuels that were supposed to wean the country off corn haven't yet materialized. Every day without those cleaner-burning fuels, the ethanol industry stays reliant on corn and the environmental effects mount.
The EPA could revisit its model and see whether ethanol is actually as good for the environment as officials predicted. But the agency says it doesn't have the money or the manpower.
With the model so far off from reality, independent scientists say it's hard to make an argument for ethanol as a global warming policy.
And the administration rarely tries to make that argument anymore. What was once billed as an environmental boon has morphed into a government program to help rural America survive.
"I don't know whether I can make the environmental argument, or the economic argument," Vilsack said in an interview with the AP. "To me, it's an opportunity argument."
Going to Congress and rewriting the law would mean picking a fight with agricultural lobbyists, a fight that would put the administration on the side of big oil companies, which despise the ethanol requirement. So the ethanol policy cruises on autopilot.
Bob Dinneen, president of the Renewable Fuels Association, said there's no reason to change the standards. Ethanol still looks good compared to the oil industry, which increasingly relies on environmentally risky tactics like hydraulic fracturing or pulls from carbon-heavy tar sands.
Leroy Perkins, the farmer agonizing about what to do with his 91 acres, says he likes ethanol as a product and an industry. But he knows corn prices are transforming his county.
"If they do change the fuel standard, you'll see the price of corn come down overnight," he said. "I like to see a good price for corn. But when it's too high, it hurts everybody."