Synchronizing nitrogen cycling processes reduces agricultural nitrous oxide and ammonia emissions.

Mitigating reactive nitrogen losses is essential for sustainable agriculture. However, predicting the benefits of substituting synthetic fertilizers with organic amendments remain unreliable because conventional approaches treat soil nitrogen processes in isolation. Here, we adapt a synchrony metric from community ecology to quantify the coordination among nitrogen processes. Using 2,235 global paired observations (organic vs. synthetic), we find that the synchrony metric predicts nitrous oxide (N2O) and ammonia (NH3) emissions more accurately than individual processes alone. Specifically, synchrony deviations in nitrification and denitrification account for half of global N2O variability, while synchrony deviations in mineralization and immobilization explain over one-third of NH3 variability. Projections indicate that leveraging organic substitution could achieve the greatest N2O reductions in European croplands (-40.7%) and the highest NH3 mitigation in Africa croplands (-46.1%). These findings establish process synchrony as a mechanistic framework for improving nitrogen gas loss models and inform targeted organic amendment strategies.