Thursday, November 09, 2023

Carbon sequestering by farmers has potential, but might not be the 'pie-in-the-sky-dream' many thought it could be

Successful Farming photo
Even with no-till and cover crop practices, carbon sequestering may not be the panacea many claimed it was, reports Laurie Bedlord of Successful Farming. "Much fanfare accompanies programs that pay farmers to sequester greenhouse gases such as carbon dioxide, methane, and nitrous oxide in their soils. Yet, questions linger as research casts doubt on whether the promise equals reality."

Gregg Sanford, a senior scientist at the Department of Agronomy at the University of Wisconsin-Madison, told Bedlord, "I worry that we are selling ourselves a pie-in-the-sky dream we might not realize, and that it could come back to bite farmers and ultimately not get us any further down the road toward reducing greenhouse gases in the atmosphere." In 2009, Sanford started analyzing soil samples from different crops and found "across the board" soil carbon loss. Bedlord reports, "It is only in their grassland systems, whether it's rotation-ally grazed pasture, CRP, or prairie, where they can document carbon sequestration in the surface soils. However, Sanford says that in many cases, they are still observing losses of carbon at depth."

Soil carbon sequestration remains unpredictable, so researchers suggest farmers target its use. Bedlord reports, "One of the caveats with soil carbon sequestration, Sanford says, is there are places in the United States where certain types of ag management will be able to build soil carbon resources, but results may vary." 

For soil carbon resources to increase, an agricultural transformation may need to happen, and natural processes in the Midwest could show how. Sanford told Bedlord, "The area in the U.S. we now call the Corn Belt was once almost entirely covered by tallgrass prairie with deep-rooted perennial plants, grazing animals, and regular fires. Over thousands of years, the prairies created the fertile, carbon-rich soils . . . . It took a long time for those deep-rooted, diverse, and perennial prairies to accumulate that soil carbon." Bedlord reports, "If the prairies built these soils, should we consider emulating what they can do in our production systems? It's a question Sanford and others are asking. . . . As with any new concept, healthy skepticism about soil's ability to sequester carbon is a good thing."

To get more information about farmers' opinions and experiences with carbon programs, click here.

No comments: