Micronutrient Management of Nitrous Oxide Emissions

Agriculture is the primary anthropogenic source of nitrous oxide (N2O), a potent greenhouse gas, and mitigating soil emissions without compromising food security is critical for climate targets. We assess the role of copper (Cu), as a micronutrient, in regulating nitrogen cycling enzymes. Using mesocosm experiments and long-term field trials, we demonstrate that Cu addition, coupled with pH modification, significantly reduces N2O fluxes. Metagenomic and metatranscriptomic analyses reveal that Cu availability regulates the expression of moxA (a Cu-containing enzyme) and its coupling with nitrous oxide reductase (nosZ). These findings suggest that targeted Cu amendments—via direct application or silicate-enhanced weathering—offer a scalable strategy to decrease agricultural N2O emissions while maintaining soil productivity.