The ALFAM2 Project - Ammonia Loss from Field-Applied Manure

Welcome to the ALFAM2 project on ammonia emission from field-applied manure. This objective of this collaborative project is to develop tools for understanding and predicting ammonia loss from field-applied manure. On this page you can find the two primary project products: emission measurements and a model.


October 2022. A new version of the ALFAM2 dataset is now available from the ALFAM2-data repository and the database web app. This version includes new measurements from Canada, Denmark, Italy, The Netherlands, and Sweden.

February 2022. The ALFAM2 model is being used as a core of a new tool for emission inventory calculations in the ALFAMI project, funded by the Thünen Institute (Germany). To submit measurements for model evaluation and refinement, or to participate in a stakeholder meeting send a message through this form.

October 2021. The ALFAM2 R package vignette (introduction and tutorial) has been updated. Use the link to the left to download a copy.

September 2021. The ALFAM2 model was recently used to calculate new emission factors for the Danish Environment Ministry. You can download a detailed report describing the methods and presenting the new emission factors here.

September 2021. New versions of the ALFAM2 model are available: R package v1.1 and Excel model v2.3. Both include the latest parameters (Set 2). Use the links to the left or below.

The ALFAM2 database

The ALFAM2 database contains original measurements on ammonia emission from animal manure applied in field trials, along with supporting information. The current version has data from more than 2,200 plots and more than 50,000 measurement intervals. The plot below shows average flux for all measurement intervals in the database within the first 5 days or so, with a different color for each application method.

For a simple interface to the database that includes filtering, see the ALFAM2 database web app:

For dataset version history or to report errors in the data, please see the ALFAM2-data repository on GitHub:

For more details on the ALFAM2 database, check out our paper in Agricultural and Forest Meteorology.

To submit data, please send an email message to sasha.hafner(at) A data submission template is available here.

The ALFAM2 model

The ALFAM2 model is a semi-empirical (semi-mechanistic) dynamic model that predicts ammonia emission from field-applied slurry in response slurry properties, management, and weather. The figure below shows the general structure of the model.

There are two interfaces: the ALFAM2 R package provides the most power and flexibility, but requires some basic understanding of R, while the Excel version is very easy to use but not as flexible. 

For more details on the ALFAM2 model, check out our paper in Atmospheric Environment.

Looking for the original ALFAM model?

Compared to the new model, it is based on older data, a less flexible approach, and does not include acidification or incorporation timing, but you can download it here.

Mailing list

Sign up for the mailing list to receive infrequent updates by sending a message to sasha.hafner(at)


This project was led by Sasha D. Hafner and Sven G. Sommer. The database contains measurements made by many reseachers. The following individuals contributed data: Jesper Nørlem Kamp, Johanna Pedersen, Sven G. Sommer, Massimo Zilio, Fabrizio Adani, Francisco Salazar, Ester Scotto di Perta, Stefania Pindozza, Andreas Pacholski, Shabtai Bittman, William Burchill, Wim Bussink, Martin Chantigny, Marco Carozzi, Sophie Génermont, Christoph Häni, Martin N. Hansen, Jan Huijsmans, Derek Hunt, Thomas Kupper, Gary Lanigan, Benjamin Loubet, Tom Misselbrook, John J. Meisinger, Albrecht Neftel, Tavs Nyord, Simon V. Pedersen, Jörg Sintermann, and Rodney B. Thompson. Sasha D. Hafner, Simon V. Pedersen, and Sven G. Sommer (all at the University of Southern Denmark at the time) created the dataset and Jon Katz created the database interface. Sasha D. Hafner created and maintains the model, with help and constructive criticism from Christoph Häni, Roland Fuß, Nick Hutchings, Anders Peter S. Adamsen, Andreas Pacholski, Shabtai Bittman, Marco Carozzi, Martin Chantigny, Sophie Genermont, Martin Hansen, Jan Huijsmans, Thomas Kupper, Tom Misselbrook, Albrecht Neftel, Tavs Nyord, and Sven Sommer. Sasha D. Hafner, Christoph Häni, and Roland Fuß wrote the ALFAM2 R package.