Kansas State University researchers say carbon sequestration on farms can combat climate change

Researchers at Kansas State University found certain fertilizers can help improve soil health and store carbon to help combat climate change. (Jill Hummels for Kansas Reflector)

Farmers can help combat climate change and improve the health of their soil by switching to natural fertilizers and minimizing tilling, new research from Kansas State University shows.

According to a paper published in June in the Soil Science Society of America Journal , analysis from a no-till cornfield in Kansas showed that manure or compost fertilizer stored more atmospheric carbon and improved microbial diversity compared with commercial fertilizers.

In a news release about the study, Ganga Hettiarachchi, one of the lead researchers, said the results were — as far as she knows — the first evidence of the mechanisms through which the addition of natural fertilizers “improve soil health, microbial diversity and carbon sequestration.”

“Collectively, studies like this are going to help us to move forward to more sustainable, more regenerative agriculture practices that will protect our soils and environment as well as help feed growing populations,” said Hettiarachchi, professor of soil and environmental chemistry at K-State.

Sequestering carbon in soil is a significant way the agriculture sector can help lower global greenhouse gas emissions. According to the Environmental Protection Agency, agriculture was responsible for just more than 10% of greenhouse gas emissions in 2021.

Carbon dioxide in the atmosphere traps heat, creating a greenhouse effect and contributing to the overall warming of the planet. Last year was the warmest since recordkeeping began in 1880, making efforts to combat climate change increasingly urgent. According to NASA, the past 10 years have been the hottest ever.

“If we find ways to enhance carbon storage in soil, then that will help us to mitigate climate change,” Hettiarachchi said.

As part of the study, Hettiarachchi and fellow researchers looked at a Kansas cornfield that had no crop rotation and had grown corn for 22 years. Rather than breaking up soil clumps, researchers cut samples from the soil and took them to specialized laboratories where they could study how carbon and other minerals were distributed in the soil.

Not only does using manure or compost fertilizer — rather than commercial chemical fertilizers — help improve carbon sequestration, Hettiarachchi said, but it improves the health of the soil and helps it retain nutrients. Runoff of nutrients — typically nitrogen and phosphorus — through rain and irrigation pollutes streams, rivers and lakes and contributes to toxic algae blooms.

University of Kansas researchers last year predicted that climate change will result in more frequent algae blooms.

Researchers from K-State partnered on the study with Canadian Light Source and Advanced Light Source, research facilities that use synchrotron lights for scientific research.