AILSA CHANG, HOST:
There is an idea that's trendy among environmentalists these days. It's called regenerative agriculture. It means healing some of the damage that people have inflicted on soil over past centuries and in the process helping the climate by using the soil to capture carbon from the air. NPR's Dan Charles visited one of the scientists who laid the groundwork for this idea.
DAN CHARLES, BYLINE: I meet Rattan Lal on the campus of Ohio State University outside with masks. He's courteous and polite, but that can be misleading.
RATTAN LAL: I am, by nature, competitive. You are either going to be in the top one, two, three, four, or you're not going to survive.
CHARLES: Lal grew up poor in a village in India. His ticket out was a stipend, a few dollars each month to study at university. He could only keep it if his grades were in the top five in the class.
LAL: The fear that what happens if I do not got stipend, that insecurity never really left me, even when I was here.
CHARLES: He found his way to the U.S. for graduate school at Ohio State, got a PhD in soil science. And then the Rockefeller and Ford Foundations sent him to Africa to work at a new Institute of Tropical Agriculture in Nigeria. His assignment was ridiculously ambitious.
LAL: I was 25 years old in charge of a lab and given the mandate of improving quality and quantity of food production in the tropics.
CHARLES: He struggled. The problem was the soil. It was nothing like what he'd seen in Ohio or India. He'd clear a piece of the forest, and very quickly, the most fertile part of the soil, the so-called organic matter - the microbes and the decomposing roots - just vaporized or washed away, leaving behind gravelly dirt as hot and hard as a road.
Then came the moment that changed his life. A famous scientist came to visit - Roger Revelle, one of the pioneers in what we now call climate science. Lal told Revelle about his problems, and Revelle said, you know, that organic matter is going into the air as carbon dioxide, the main greenhouse gas. And then he asked a question.
LAL: Can you put it back?
CHARLES: Could the soil recapture that carbon?
LAL: That simple statement, can you put it back, was my introduction to climate and soil.
CHARLES: It stuck with you?
LAL: It stuck with me. It's still there (laughter).
CHARLES: It became his calling card when he returned to Ohio State to teach in the late 1980s. He was writing articles, giving speeches, describing the soil as a vast global reservoir of carbon that farmers are spilling into the air. And he was experimenting with ways to refill that reservoir. Nall Moonilall, a PhD student at Ohio State, shows me one of those experiments - small squares of soil at the university's research farm.
NALL MOONILALL: This is the west mulch experiment, and it was set up, I believe, back in 1989.
CHARLES: Some of the plots have been covered with mulch made of straw every year. Others stay bare. Those bare soil plots now contain less than 1% carbon.
MOONILALL: Versus the carbon content in a plot that receives maximum amount of mulch is probably upwards of 4%.
CHARLES: That's a huge difference. Extended across all American cropland, that would be billions of tons of additional carbon back in the ground. And it makes the soil better. It's more fertile, holds more water.
LAL: The lifeblood of soil is the organic matter content.
CHARLES: And there are ways to preserve it, to build it up. Stop tilling the soil. Keep it covered, ideally with living vegetation.
LAL: As soon as that happens, the life-giving process begins to start. It's a slow process.
CHARLES: But all of a sudden, it's glitzy. There are TED talks about soil health. Companies are promising to pay farmers to do things that capture carbon. One company, Indigo Carbon, released this video.
(SOUNDBITE OF VIDEO)
UNIDENTIFIED PERSON: What if I told you that the most promising technology we have to address climate change is growing on 3.6 billion acres across planet Earth?
CHARLES: There are critics who say the movement's become a fad, that it's not possible to capture enough carbon to really help the climate unless you make bigger changes, like actually reducing the amount of land used to grow crops. But Rattan Lal's just happy the soil is finally getting the respect it deserves. He wants it written into law. We have a Clean Air Act and a Clean Water Act, he says, let's pass a Healthy Soils Act. Dan Charles, NPR News.
(SOUNDBITE OF MUSIC)
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.