Farmers, more than anyone else, manage America's land and water. They grow crops or graze cattle on more than half of the country's land outside of Alaska.

"Farming has huge impacts on water. Huge impacts on wildlife. It has big impacts on air, especially from animal feeding operations," says Craig Cox, senior vice president for agriculture and natural resources at the , or EWG, a nonprofit environmental organization. Agriculture, for example, has been blamed for in Lake Erie, high levels of nitrates in Iowa's rivers and a giant "dead zone" in the Gulf of Mexico. Plowing and draining the Great Plains to make way for crops has driven many species of animals, like the black footed ferret, closer to extinction.

Yet according to many environmentalists, the federal government does little to regulate farmers. If anything, they say, the government makes things worse by providing subsidies that cushion farmers from the impact of low prices, encouraging them simply to plant more corn and soybeans, the crops that cover most of the Midwest.( created a decade ago by EWG shows exactly how much money each American farmer has been receiving from the government.)

But the government also provides some financial incentives for farmers to reduce their environmental impact. Farmers get government checks if, for instance, they voluntarily agree to plant strips of grass along streams, or create habitat for butterflies and native bees, or upgrade irrigation systems in order to use water or energy more efficiently.

These dollars are the government's main tool for getting farmers to do things that aren't in their economic self-interest, but which benefit the environment.

"We've been a huge supporter of these programs," says Cox. "But it's been difficult to know what they were doing."

Now it's possible to know a little more. This week, the EWG unveiled a database of "conservation" payments. They add up to almost $5 billion this year, or roughly a quarter of all farm subsidies.

Cox and his colleagues filed 28 separate requests under the Freedom of Information Act to collect details on every conservation payment, then assembled it all into a database. Anyone now can go online to see where the money went and what agricultural practices it was supposed to encourage.

"Now we can have an intelligent conversation about [these programs]," Cox says. "Are these are the right practices? Are payments going to the right places? Should we adjust the way these programs operate in order to make them more effective?"

Cox thinks the government could buy more environmental progress for its $5 billion a year.

Many years ago, he says, the USDA used the term "conservation" to describe farm improvements that simply improved profitability. "We paid farmers to drain wetlands until 1977," he says.

A vestige of that idea persists in "conservation" payments today, he says. Take, for example, the payments farmers can receive for upgraded irrigation equipment or tools for applying fertilizer where it's most needed. The payments should be focused on producing real public benefits to taxpayers, Cox says. For example, reducing fertilizer runoff into streams and rivers would improve water quality, and thereby benefit public health and quality of life. "You should be able to float down the Skunk River in Iowa and not be disgusted by the experience," he says.

A recent report from the USDA's Economic Research Service also called for greater attention to the "major challenge" of making the agency's environmental payments more cost-effective. It pointed out that "a large share of pollution originates on a relatively small number of farms and fields," but because participation in the USDA conservation programs is voluntary, it's impossible to guarantee that those farms improve their practices.

The USDA's environmental payments are "incredibly important," says Linda Prokopy, a researcher at Purdue University who has interviewed farmers about their environmental practices. "If farmers didn't have access to these payments, they couldn't afford to adopt new practices" such as cover crops, which reduce both soil erosion and fertilizer runoff.

The payments are "necessary, but not sufficient" to change farmer behavior, she says. "Many farmers are not willing to change their practices."

The USDA has tried, with mixed success, to aim conservation payments at specific "conservation priority areas," such as limiting agriculture on steeply sloping land that is prone to soil erosion and fertilizer runoff.

"We've heard, anecdotally, that there's a lot of resistance in Congress to targeting the money," Prokopy says. "But farmers understand that not all land is created equal. Farmers completely understand the need to target these incentives" toward land that requires more protection.

According to Prokopy, most farmers are interested in environmentally beneficial practices that offer some benefit to their bottom line as well. Cover crops, for instance, are supposed to reduce pollution in nearby streams, but they also promise a farmer more fertile soil and lower fertilizer bills. "It's very hard to convince a farmer to adopt a practice that only has a downstream benefit," she says.

According to Cox, this shows that the USDA shouldn't just rely on the carrot of financial incentives when persuading farmers to change their practices, but also on the stick of regulations. "We can't buy our way out of the increasing environmental issues that are mounting out there in the landscape," he says. "There's never going to be enough money."

Cox says it's time to demand that farmers carry out environmental improvements if they receive any federal subsidies at all. Most of these payments act as an economic safety net for farmers. These conventional subsidies, not counting conservation payments, are estimated to reach $14 billion this year.

Copyright 2021 NPR. To see more, visit https://www.npr.org.