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 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.

August 2021. The ALFAM2 database is growing. We are currently working with researchers to add new measurements. Check back here in a few months or sign up for the mailing list for updates.

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 1800 plots and more than 30,000 measurement intervals. The plot below shows average flux for all measurement intervals in the database.

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)

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: 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 database. Sasha D. Hafner created and maintains the model, with help from Anders Peter S. Adamsen, Andreas Pacholski, Shabtai Bittman, Marco Carozzi, Martin Chantigny, Sophie Genermont, Christoph Häni , Martin Hansen, Jan Huijsmans, Thomas Kupper, Tom Misselbrook, Albrecht Neftel, Tavs Nyord, and Sven Sommer. Sasha D. Hafner and Christoph Häni wrote the ALFAM2 R package. Anders Peter S. Adamsen and Johanna Maria Pedersen made suggestions on the vignette.