A new study by researchers of the Chinese Academy of Sciences shows that the amount of ammonia (NH₃) released from agricultural soil varies significantly throughout the year. This finding has crucial implications for understanding air quality and managing nitrogen pollution.

Ammonia is a gas known to contribute to both air pollution, including harmful PM_2.5 particles, and the nitrogen cycle that affects plant growth and ecosystems. Accurately measuring ammonia emissions is essential for controlling regional air pollution.

The study, published in Environmental Science & Technology, tracked ammonia emissions throughout the maize growth cycle. Researchers found that the "fingerprint" of the ammonia, measured by its isotope ratio, changed significantly between seasons. Specifically, emissions in May-June were isotopically distinct from those in July-October.

This isotopic difference allows scientists to pinpoint the sources of ammonia emissions. The study revealed that neglecting the seasonal change in ammonia's fingerprint would lead to overestimating its contribution to air pollution in the warmer months.

These findings highlight the importance of considering seasonal variations in ammonia emissions when managing air quality and developing pollution control strategies.

The study was led by the Stable Isotope Ecology Group at the Institute of Applied Ecology of the Chinese Academy of Sciences. The research was funded by national programs on atmospheric pollution research and control.