A research team from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences has developed a novel, non-destructive method for the rapid measurement of leaf ammonia emissions.

The results published in Plant Physiology and Biochemistry, offer a new approach that could significantly improve nitrogen (N) management in agricultural practices.

A deep understanding of ammonia emissions in farmlands can greatly support efficient nitrogen (N) management in crop production. However, due to lack of rapid measurement methods, little is known about leaf ammonia emissions.

The new electrochemical sensor-based approach introduced in this study allows for precise and non-destructive monitoring of leaf ammonia emissions with remarkable repeatability, accuracy, and selectivity. 

"The sensor's response time ranges between seveen and 22 seconds," said Dr. YANG Yang, a member of the team, "making it suitable for rapid in-field measurements."

Utilizing this method, the researchers observed variations in ammonia emission rates across different foliar ranks in maize. They discovered that leaf ammonia emission rates were closely linked to several key leaf traits, including chlorophyll concentration, nitrogen content, and photosynthetic rate. These findings suggest that ammonia emissions could serve as an indirect indicator of a plant's physiological status and growth condition. 

"Our findings provide new tools to promote research on crop nitrogen management and nitrogen nutrition physiology," said Dr. YANG.

The work was supported by the National Natural Science Foundation of China.

Measuring leaf ammonia emissions with the new method (a) and traditional method (b) (Image by YANG Yang)

Real-time measurements of leaf ammonia emissions with the new method (Image by YANG Yang)