Perspective: Farming with crops and rocks to address global climate, food and soil security (Nature Plants)

Rising atmospheric CO₂ levels are causing wide-ranging climate abnormalities. Beerling et al. discuss ways to capture CO₂ in soils through augmenting soils with crushed basalt, or silicate-rich wastes such as sugarcane mill ash. As the added rock weathers, it reacts with gaseous CO₂ to release cations (Ca²⁺ and Mg²⁺) and alkalinizing bicarbonate ions (HCO₃^–), which when leached into oceans can counteract increasing ocean acidity. Thus, enhanced weathering delivers three benefits: lowering atmospheric CO₂, enhancing the availability of nutrients in soil, and counteracting ocean acidification. The authors discuss pros and cons of different types of rock (some are high in harmful Ni and Cr and so detrimental to plant life) and the energetic and economic costs, as well as areas where additional research is suggested. They conclude that “farming with rocks”  is an approach that should be explored further as an effort to achieve the UN’s Sustainable Development Goals. (Summary by Mary Williams) Nature Plants 10.1038/s41477-018-0108-y