Prairie Soils Key To Global
Warming — Assuming It Exists

WICHITA, Kan. —(AP)— For decades, the soils of the Kansas prairie have fed the world, making the state the nation's top wheat producer and number three in beef.

Now the rich dirt of the Kansas prairie may hold one of the keys to solving so-called "global warming."

Prairie, even prairie that has been plowed under and planted to crops, can act as a giant vacuum cleaner, sucking pollution out of the air and storing it underground, where it is safely locked away for a thousand years.

The implications, say researchers, are huge.

Research under way at Kansas State University and other land grant universities in the Midwest could transform the image of agriculture, supposedly a large contributor to global warming, from one of its villains into one of its heroes.

And if the research gains political acceptance, it could help hold off painful solutions to global warming — like $3-a-gallon gasoline and a large increase in home heating bills.

``It is not going to solve the problem,'' said Charles Rice, a soil microbiologist at K-State, and one of the principal researchers into the carbon-absorbing capabilities of dirt. But it could buy enough time, he said, for scientists to make nonpolluting energy sources such as solar and wind power more cost-effective.

Global warming is caused when fuels, such as coal and gasoline, are burned and release heat-trapping carbon dioxide into the air.

In a reverse of the greenhouse effect, plants take carbon dioxide out of the air and convert it to food and oxygen. The excess carbon goes into the soil.

Rice and others have found that some simple changes in farming techniques — such as not plowing the soil and adjusting crop rotations so that land is left fallow for shorter periods — can keep the carbon locked up in the soil for hundreds, if not thousands, of years.

``The main thing is that ag can be part of the solution,'' he said.

Up until now, when politicians have talked of curbing global warming, they have talked about curbing the use of the energy that powers our factories, drives our cars and heats our homes, a move that some fear would be an economic disaster.

The idea that some changes on the farm could reduce global warming is so promising and so potentially painless that Pat Roberts and five other senators are pushing for more research into the carbon-absorbing powers of agriculture.

But there is a catch. President Bill Clinton has signed the Kyoto Protocol, an environmental agreement mandating that the United States cut greenhouse gas emissions to 93 percent of 1990 levels. It's not clear whether reductions attributed to prairies will meet international obligations under the protocol.

(That's not a big problem; unless and until the Senate ratifies the treaty, this country's "obligations" are only as good as Bill Clinton's word. And there's not a snowball's chance in Presidio for ratification. — Ed.)

John Harrington, head of the geography department at Kansas State, just completed a three-year government study into the attitudes of western Kansans about global warming.

He found that global warming is a lot like the tooth fairy — everyone has heard of it, but they don't necessarily believe in it.Even the dire predictions by the Environmental Protection Agency that global warming could mean more drouths followed by more floods in Kansas don't frighten people who have lived through the Dust Bowl era.

At K-State, research into whether the prairie could solve global warming problems started in 1989, when Rice, Clenton Owensby, a range management research agronomist, and others began studying how the prairie would respond to global warming.

Their interest was purely financial. They wanted to know whether doubling the amount of carbon dioxide in the atmosphere — something that is predicted to happen in the next century — would affect weight gains for cattle that graze in the Flint Hills.

Owensby built a plastic bubble about 12 feet in diameter, put some sheep inside to graze and began pumping in carbon dioxide.

What the researchers found surprised them.

The prairie thrived. The sheep thrived. Part of the reason was that the tiny openings in the plant cells, called stomates, that take in carbon didn't have to open as much, allowing the plants to conserve water.

They also found a 10 percent increase in the amount of carbon stored in the soil in their test patch of prairie.

That may not sound like much, Owensby said, but it is a lot like growing old. Small changes add up over time.

They began looking at whether cropland could absorb carbon.

The answer lies in the farming technique, not in the dirt. Plowing breaks up the soil particles, allowing microbes to use the carbon and release it to the air.

But if the ground is planted through no-till planting, the carbon remains locked up and protected.

Increasing the amount of carbon in the soil has other benefits as well. It reduces water pollution, improves soil quality, increases crop yield and reduces the need for fertilizer.

``It's a win-win solution,'' Rice said.