New way to farm boosts climate, too
‘Organic no-till’ combines best of two methods and sequesters most carbon. But can it work consistently?
Some scientists say an ice age was prevented thousands of years ago by the dawn of human agriculture – deforestation and farming released enough greenhouse gases into the atmosphere to prevent another global cool down, the theory goes.Skip to next paragraph
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Now, millennia later, researchers hope new farming techniques will put some of that carbon back into the ground and help stem the rising tide of global warming.
No-till agriculture, in which farmers don’t plow their fields anymore, is one practice said to promote carbon sequestration in the soil. Organic farming is another. Researchers here at the nonprofit Rodale Institute are now developing a hybrid “organic no-till” farming system that they say could sponge up more carbon than any other way of growing food.
The claim: If organic no-till agriculture were used successfully on all of the earth’s 3.5 billion tillable acres, it would absorb and sequester more than half of all present-day CO2 emissions every year, according to Rodale Institute research director Paul Hepperly.
At the same time, the practice would also curb soil erosion and the dangers of chemical runoff.
“No-till organic is probably one of the best systems for helping to sequester carbon,” says John Reganold, a soil scientist who has studied sustainable agriculture at Washington State University at Pullman for 25 years. “What Rodale is doing is the best of both worlds.”
Jeff Moyer, farm director at The Rodale Institute, says his quest for organic no-till began as a fortuitous accident 18 years ago. As part of an agricultural experiment, researchers had planted a field with a cover crop called hairy vetch. One end of the field wasn’t part of the experiment, though, so they just drove over it with tractors, crushing down the cover crop in the process.
Some time later, after the field had been planted with corn, Mr. Moyer noticed something interesting was happening where the tractors had trampled everything: Corn plants were growing through the crushed vetch crop, which now looked like a mat of brown cardboard and was acting as a sort of mulch.
“Everybody stood there and looked at it and went, ‘Wow, you did organic no-till,’ ” says Mr. Moyer. “So we’ve spent the last 18 years trying to figure out a system that will allow us to replicate that accident over and over and over again.”
The paradigm shift represented by organic no-till is that it strives to eliminate the use of both herbicides and tillage. But for it to work effectively, the cover crop suppressing the growth of weeds must be knocked down in just the right way and at just the right time. This lets a farmer plant cash crops directly through the cover crop at the same time it’s being rolled down.
In 2002, after experimenting for more than a decade with existing farm equipment, Mr. Moyer custom-engineered a corkscrewed roller-crimper that does the knockdown job from the front end of a tractor. The first roller-crimper prototype was built in a neighbor’s weld shop and now, seven years later, they are being sold commercially by an independent manufacturer. Dozens are being used across the country by agricultural researchers and early-adopter farmers.
Bill Mason, a farmer on Maryland’s Eastern Shore, is one such early adopter. His reason for the switch had nothing to do with carbon sequestration; he was drawn by another promise of organic no-till: better economics. Organic crops sell for more than conventionally raised ones, while no-till cuts down on tractor use, reducing a farmer’s fuel and labor costs.