Agricultural liming is a large carbon sink in the Mississippi River Basin - Preprint

[Geoengineering News]

https://www.researchsquare.com/article/rs-7068561/v1

Authors: Tim Jesper Suhrhoff, Christopher Reinhard, Yoshiki Kanzaki, Samuel Shou-En Tsao et al.

19 June 2026

https://doi.org/10.21203/rs.3.rs-7068561/v1

Abstract

The application of carbonate minerals to arable lands — agricultural liming — is a long-standing practice for counteracting soil acidification due to atmospheric pollution and anthropogenic fertilizer addition1–3. While this practice boosts crop yields and mitigates soil acidification4, it is widely considered to be a significant component of agricultural emissions of carbon dioxide (CO2)5. Here, we use a multi-decade timeseries of agricultural liming and anthropogenic acidity for the Mississippi River Basin — one of the largest agricultural catchments on Earth — together with results from reactive transport modeling to show that agricultural liming has acted as a net carbon sink over the last century. We show that ~75% (65-85%) of the maximum carbon dioxide removal potential of agricultural lime added since 1900 has been realized on the catchment scale, with a time lag due to soil cation exchange and solute transport of roughly ~15 years. Our results suggest that it is the addition of anthropogenic acidity to agricultural systems that should be thought of as an emissions source, rather than the addition of lime, and underscore that optimized soil pH management can significantly reduce agricultural greenhouse gas emissions while augmenting crop yields and soil health.

Source: ResearchSquare