NOAA Begins Study to Quantify Agricultural Ammonia Emissions

April, 2014

From May 1 through early fall, 2014, NOAA’s Air Resources Laboratory (ARL) will co-lead a study on atmospheric ammonia in an intensively managed agricultural system. This study is funded by the National Science Foundation and will be conducted in collaboration with the University of Illinois at Urbana-Champagne (UIUC). Scientists at ARL’s Atmospheric Turbulence and Diffusion Division will operate an ARL-designed flux-gradient system to determine ammonia fluxes from planting through harvesting of a maize crop at the UIUC’s Energy Biosciences Institute, a 320-acre farm which is the world’s largest outdoor research center devoted to bioenergy crops. The measurements collected will be invaluable to improving the understanding of processes and parameters that drive and influence ammonia emissions, which will also lead to improved predictions of ammonia behavior in air quality models.

Background: ARL has a long history in air-surface exchange research. As part of its atmospheric chemistry program, ARL conducts ongoing studies of ammonia in different regions of the country. The current study will build upon previous experiments and leverage ARL’s unique capabilities by providing ammonia flux data from multiple measurement systems, both above-canopy and in-canopy, for an entire growing season, which is a first of its kind study in the Midwest US. Measurements will be incorporated into a suite of models to differentiate between plant and soil exchange processes and better characterize the spatial and temporal distribution of ammonia emissions. In addition, data collected during the field study will be used to validate regional ammonia emissions estimates using a Geographic Information System (GIS) framework.

Significance: Ammonia is a gas that contributes to poor air quality by playing a role in the formation of fine particulate matter. It is also a form of reactive nitrogen (a nutrient) that can contribute to a ‘cascade of effects’ in terrestrial and aquatic ecosystems, including soil acidification, coastal water eutrophication, and loss of biodiversity. Ammonia emissions from agriculture (animal waste and commercial fertilizers) have increased dramatically in recent years and account for more than 80 percent of total emissions worldwide. Yet, large uncertainties in ammonia emissions inventories persist, in part due to a lack of field measurements. This study is a much needed enabling step to accurately quantify ammonia from an intensive agricultural area.

For More Information, contact: LaToya Myles