Submitted to: Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 2/20/2006
Publication Date: 3/21/2006
Citation: Rotz, C.A. 2006. Process-based modeling of gaseous emissions from dairy farms. Western Dairy Air Quality Symposium. p. 3-5. Interpretive Summary: An interpretive summary is not required.
Technical Abstract: Gaseous emissions to the atmosphere are a growing concern in animal agriculture including dairy farms. Compounds of most concern include ammonia, hydrogen sulfide, volatile organic compounds, and greenhouse gases such as methane and nitrous oxide. Measuring the loss of these gases from farms is difficult, often inaccurate, and very expensive. Losses are also dependent upon farm management, so large differences can occur among farms. For these reasons, a process-based modeling approach has been recommended for estimating farm emissions and the effects of management on these emissions. To meet this need, a model is being developed that includes process-based simulations of gaseous emissions from housing facilities, manure storages, field applied manure, and grazing animals on a dairy farm. These major processes are simulated through time over many years of weather to obtain long term estimates of maximum and average emissions. The primary objective is to create a relatively simple and easy to use software tool that predicts each of the major emissions from dairy farms on both a daily and annual basis. The model will be validated against data gathered over the next two years through the monitoring of five or more dairy facilities throughout the US. This science-based and farm validated tool will then be made widely available for evaluating the gaseous emissions from dairy farms. By simulating various management practices, the tool will be used to evaluate the potential benefits of various technologies and strategies developed for reducing gas emissions. The algorithm for simulating gas emissions will also be integrated into a whole-farm simulation model to provide a research tool for more extensive evaluation of the interaction between gas emissions and other farm processes, including water quality impacts and farm profitability. This farm simulation model will be made available to other researchers and educators working on whole-farm impacts of technologies and strategies used to reduce the environmental impacts of dairy farms.