U.S. Farmers Exploring Soil Carbon Storage as a Sustainable Practice

Several decades ago, Iowa farmer Al Schafbuch reduced plowing and introduced cover crops to his fields, aiming to cut fertilizer costs and decrease erosion. The result? His soil became dark, rich, and organic – he likened it to “chocolate cake”. An unexpected benefit soon emerged: these farming techniques store more carbon. Increased plant growth absorbs more CO2 while fewer soil disturbances reduce carbon release. These approaches can lead to financial benefits for farmers through carbon offsets – payments made by companies to support carbon storage to counterbalance their emissions. As Shalamar Armstrong, an agronomy professor at Purdue University, put it, “Storing atmospheric carbon through crops offsets energy waste.”

Focus on agricultural emissions is intensifying as the U.S. Department of Agriculture pledged a $300 million investment to monitor them. U.S. Senators, Tina Smith and Todd Young, introduced a bill backing the research to effectively credit soil carbon storage. Accurately quantifying soil carbon is a challenge that is paramount for the burgeoning soil carbon market, which faces skepticism akin to other carbon credit markets.

Cristel Zoebisch from Carbon180 noted the lack of comprehensive research on carbon credits concerning monitoring and verification. To fill this research gap, Armstrong’s lab at Purdue University is assessing how farm management influences soil carbon levels. Using soil samples spanning over four decades, they are comparing various tilling methods and cover crops to understand carbon storage implications. Despite rigorous research, questions remain.

MIT‘s Professor John Sterman believes that for carbon offsets to be truly effective, they must meet four criteria: verifiability, immediacy, longevity, and the feature of storing carbon that would’ve otherwise been released. While research may make offsets more verifiable, other criteria, like longevity, present complications. Given that many farmers lease land, ensuring long-term carbon storage is problematic.

Barbara Haya from the University of California believes carbon trading, as a mechanism, hasn’t been successful historically. U.S. Rep. Jared Huffman introduced a bill supporting farmers in enhancing soil health, emphasizing that relying solely on offsets isn’t the complete solution.

While some farmers, like Brad Wetli from Indiana, are cautiously approaching these practices and considering the financial implications of carbon credit contracts, others like Schafbuch, though skeptical of carbon credits, champion regenerative farming. He recalls being initially mocked for his choices but remains confident, “If done right, anyone can do it.”