Soil’s ability to trap carbon dioxide is potentially much greater than previously estimated, according to Stanford researchers who claim that soil health could “significantly” offset increasing global emissions.
Two papers published October 5 in Annual Review of Ecology, Evolution and Systematics and Global Change Biology, emphasize the need for more research into how soil – if managed well – could mitigate carbon emissions.
It’s “a no-risk climate solution with big co-benefits. Fostering soil health protects food security and builds resilience to droughts, floods and urbanization,” said Rob Jackson, lead author of the Annual Review of Ecology, Evolution and Systematics article and co-author of the Global Change Biology paper.
According to the research, soil organic matter such as decomposing plant and animal residues stores more global carbon than do plants and the atmosphere combined. But soil carbon stocks are compromised through land-use changes and unsustainable forest and agricultural practices. To understand and restore soil organic matter, the researchers call for better appreciation of soil organic carbon saturation capacity and the retention of above and below ground inputs in the soil. Their analysis suggests roots are approximately five times more likely than leaves to turn into soil organic matter for the same mass of material.
The researchers recommend improving how the land is managed, which could increase soil’s carbon storage enough to offset future carbon emissions. Possible approaches include: reduced tillage, year-round livestock forage and compost application. Planting more perennial crops, instead of annuals, could store more carbon and reduce erosion by allowing roots to reach deeper into the ground.