Saturday, September 05, 2009

Carbon offsets for no-till farming no simple thing

No-till farming is one method for cutting carbon emissions that would be rewared by the climate-and-energy bill that has passed the House and is in the Senate, but some have questioned the practicality of the process. The bill would offer no-till farmers offsets that they can sell to companies that would have to decrease their carbon emissions.

Organic matter in no-till soil can be as high as two percent, twice as much as plowed soil, but researchers have discovered plowed fields hold as much or more carbon three or four feet below the surface, and while no-till farming stores more carbon in the soil, the benefit lasts only as long as the land isn't tilled, Christopher Joyce of National Public Radio reports.

The bill encourages farmers to remove crop residue after a harvest to make ethanol, but Ohio State University soil scientist Rattan Lal tells Joyce that removing crop residue negates the benefits of no-till farming. "That's a no-no," Lal says. "The moment you take the crop residue away the benefit of no-till farming on erosion control, water conservation and on carbon sequestration will not be realized." Lal tells Joyce that he still supports no-till farming because it means the farmer isn't using fossil fuel to run a plow and make fertilizer. (Read more)

No comments: