Potential of global croplands and bioenergy crops for climate change mitigation through deployment for enhanced weathering.

Conventional row crop agriculture for both food and fuel is a source of carbon dioxide (CO2) and nitrous oxide (N2O) to the atmosphere, and intensifying production on agricultural land increases the potential for soil C loss and soil acidification due to fertilizer use. Enhanced weathering (EW) in agricultural soils-applying crushed silicate rock as a soil amendment-is a method for combating global climate change while increasing nutrient availability to plants. EW uses land that is already producing food and fuel to sequester carbon (C), and reduces N2O loss through pH buffering. As biofuel use increases, EW in bioenergy crops offers the opportunity to sequester CO2 while reducing fossil fuel combustion. Uncertainties remain in the long-term effects and global implications of large-scale efforts to directly manipulate Earth's atmospheric CO2 composition, but EW in agricultural lands is an opportunity to employ these soils to sequester atmospheric C while benefitting crop production and the global climate.