New research from the Georgia Institute of Technology suggests that liming, a long-standing agricultural practice used to neutralize acidic soils, may play a significant role in both improving crop yields and reducing atmospheric carbon dioxide. The findings challenge the prevailing view that liming necessarily increases greenhouse gas emissions.
Chris Reinhard, an associate professor in the School of Earth and Atmospheric Sciences at Georgia Tech, explained: “The current thinking about liming is that farmers must choose between doing something that could benefit them economically or reducing their greenhouse gas emissions. But this is often a false choice. They can do both.”
The research team published their framework for understanding the dual benefits of liming in the August issue of Nature Water under the title “Using Carbonates for Carbon Removal.” Their work examines how adding crushed calcium- or magnesium-rich rocks to soil not only addresses soil acidity but also impacts greenhouse gas levels.
As part of a Department of Energy study, Reinhard and his colleagues have been analyzing the effects of liming on farms in the Upper Midwest’s Corn Belt. With additional support from the Grantham Foundation, they are expanding their studies to farms in southern Georgia and North Carolina. For each location, researchers collect standard agricultural data such as soil pH and nutrient content, as well as more specialized information like trace elements and measurements of greenhouse gas fluxes.
These data points are integrated into a machine learning model designed to predict how carbon dioxide and other gases behave within specific soil systems. The model accounts for variables including crop rotation, climate conditions, and management practices. Reinhard noted: “Our goal is to develop a way that farmers can monitor and plan cheaply, and largely through techniques they are already using, so we don’t have to send out a whole team to gather data. We are trying to develop a predictive model architecture for planning agricultural practice across scales, but it’s important that the techniques required on the field are actually feasible for farmers.”
The implications extend beyond individual farms. Improved access to liming could help regions with food insecurity—such as sub-Saharan Africa—boost self-sufficiency by increasing crop yields while also potentially benefiting from reduced greenhouse gas emissions.
Researchers are also examining whether liming can lower levels of methane and nitrous oxide—two other major greenhouse gases associated with agriculture. Nitrous oxide is considered particularly challenging to reduce in farming contexts.
While liming has been practiced for centuries primarily for its agronomic benefits, this new research highlights its potential environmental advantages as well.
