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ARS Home » Pacific West Area » Kimberly, Idaho » Northwest Irrigation and Soils Research » Research » Publications at this Location » Publication #391683

Research Project: Improving Management Practices for Irrigated Western Cropping and Dairy Systems to Contribute to Sustainability and Improve Air Quality

Location: Northwest Irrigation and Soils Research

Title: Model for calculating ammonia emission from stored animal liquid manure

item SOMMER, SVEN - Aarhus University
item HAFNER, SASHA - Aarhus University
item LAUBACH, JOHANNES - Landcare Research
item VAN DER WEERDEN, TONY - Agresearch
item Leytem, April
item PACHOLSKI, ANDREAS - Thunen Institute Of Climate-Smart Agriculture

Submitted to: Biosystems Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/23/2022
Publication Date: 8/25/2022
Citation: Sommer, S.G., Hafner, S., Laubach, J., Van Der Weerden, T.J., Leytem, A.B., Pacholski, A. 2022. Model for calculating ammonia emission from stored animal liquid manure. Biosystems Engineering. 223:Part A:41-55.

Interpretive Summary: National inventories calculate ammonia emission from livestock manure using static emission factors. These do not account for local environmental condition, management practice or variation in manure composition. We present a model that estimates emission from liquid manure per area and time as related to slurry composition, temperature and surface covers. Data was extracted from articles and used to parameterize and validate the model, and the scenario calculations demonstrate the usefulness of the model.

Technical Abstract: Ammonia (NH3) emissions from agriculture have increased by 90% from 1970 to 2005, and agriculture is now the largest source of NH3 to the atmosphere. National emission inventories calculate NH3 emissions from agriculture with static emission factors not reflecting regional or local conditions. We propose a simple model to calculate emission rates which incorporates effects of temperature, pH, total ammonical nitrogen (TAN) concentration, exposed storage area,and effects of a cover. Parameters used in the model were estimated from a database comprised of 44 studies. The proposed approach was no more precise than the standard emission factors, probably due to both limitations in measurements and complex interactions that affect volatilization rates. However, the proposed approach has two advantages compared to the alternative: it does not require an estimate of TAN or nitrogen flow through the store, and calculated values reflect management (e.g., storage area, TAN concentration, or the use of a cover) and environment (temperature) based on well-established principles. If this simple and process-related approach is accepted as a suitable method then more precise parameterization of the model can be achieved by carrying out studies where the focus is on emission measurements, slurry composition characterization, air and slurry temperature and windspeed. To facilitate this approach, data need to be collected over relatively short time intervals to ensure that they represent conditions at the same time and right place.