Cropland ammonia volatilization (VNH3,AG) is a major pathway of agricultural nitrogen loss. It remains unclear, however, how climate warming and human intervention (e.g., agricultural management) will affect VNH3,AG. Here, we use a fully coupled agroecosystem/chemical transport model and multiple climate projections to quantify the changes in climate-induced VNH3,AG over the US. We show that climate change under an intensely warming scenario will increase VNH3,AG by 81% (95% confidence interval, 69%–92%) from 2010 to 2100. The increase in VNH3,AG will cause a 10% loss of nitrogen applied, decrease crop yields by 540 Gg-N year−1, increase atmospheric burden of ammonia/ammonium by 18%, and increase ammonia/ammonium deposition to sensitive ecosystems by 14%. We have found that combining climate-adaptive agricultural practices with feasible mitigation measures can fully offset the warming-induced increase in VNH3,AG, saving 13% of applied nitrogen, increasing yields by 735 Gg-N year−1, and providing net benefits for air quality and ecosystem health.
One Earth, VOLUME 3, ISSUE 1, P126-134, JULY 24, 2020,