Enhanced weathering in the U.S. Corn Belt delivers carbon removal with agronomic benefits

TL;DR

This study demonstrates that enhanced weathering with crushed basalt in the U.S. Corn Belt effectively sequesters carbon, improves soil health, and boosts crop yields, offering a scalable strategy for climate mitigation and agricultural benefits.

Contribution

It provides the first large-scale field trial data showing carbon sequestration, soil health improvements, and yield increases from enhanced weathering in a major agricultural region.

Findings

15.4 +/- 4.1 t CO2 ha-1 sequestered over four years

Crop yields increased by 12-16%

Soil nitrous oxide emissions reduced by 0.1-0.4 t CO2e ha-1 yr-1

Abstract

Enhanced weathering (EW) with crushed basalt on farmlands is a promising scalable atmospheric carbon dioxide removal strategy that urgently requires performance assessment with commercial farming practices. Our large-scale replicated EW field trial in the heart of the U.S. Corn Belt shows cumulative time-integrated carbon sequestration of 15.4 +/- 4.1 t CO2 ha-1 over four years, with additional emissions mitigation of ~0.1 - 0.4 t CO2,e ha-1 yr-1 for soil nitrous oxide, a potent long-lived greenhouse gas. Maize and soybean yields increased 12-16% with EW following improved soil fertility, decreased soil acidification, and upregulation of root nutrient transport genes. Our findings suggest that widespread adoption of EW across farming sectors has the potential to contribute significantly to net-zero greenhouse gas emissions goals and global food and soil security.