Software for evaluating greenhouse gas emissions and the carbon footprint of dairy production systems

Authors: Rotz, Clarence - Al; Montes, Felipe

Submitted to: International Conference on Greenhouse Gasses and Animal Agriculture
Publication Type: Abstract Only
Publication Acceptance Date: 8/15/2010
Publication Date: 10/3/2010
Citation: Rotz, C.A., Montes, F. 2010. Software for evaluating greenhouse gas emissions and the carbon footprint of dairy production systems [abstract]. Proceeding of the 4th Greenhouse Gasses and Animal Agriculture. p.206-207.

Interpretive Summary: An interpretive summary is not required.

Technical Abstract: Abstract: Dairy production, along with all other types of animal agriculture, is a recognized source of greenhouse gas (GHG) emissions, but little information exists on the net emissions from our farms. Component models for representing all important sources and sinks of CH4, N2O, and CO2 in dairy production were integrated in a software tool called the Dairy Greenhouse Gas Model or DairyGHG. This tool determines the carbon footprint of a production system as the net exchange of all primary and secondary GHG emissions expressed as CO2 equivalent (CO2e) units per unit of energy corrected milk (ECM) produced. Primary emission sources include enteric fermentation, manure, cropland used in feed production, and the combustion of fuel in machinery used to produce feed and handle manure. Secondary emissions are those occurring during the production of resources used to produce milk, which can include fuel, electricity, machinery, fertilizer, pesticides, plastic, and purchased replacement animals. A long-term C balance is assumed for the farm, which does not account for potential depletion or sequestration of soil carbon. Evaluation of dairy farms of various sizes and production strategies has given carbon footprints of 0.37 to 0.75 kg CO2e per kg ECM, depending upon milk production level and the feeding and manure handling strategies used. When CO2 other than combustion emissions is ignored, this range increases to 0.67 to 0.95 kg CO2e per kg ECM. In a comparison to previous studies, DairyGHG predicted C footprints similar to those reported when similar assumptions were made for feeding strategy, milk production, allocation method between milk and animal co-products, and sources of CO2 and secondary emissions. DairyGHG is available at http://www.ars.usda.gov/Main/docs.htm?docid=17355 for download and installation on computers using a Windows® operating system. This software provides a relatively simple tool for evaluating management effects on net GHG emissions and the overall carbon footprint of dairy production systems. Graphical and tabular outputs provide estimates of all important GHG sources and sinks and a breakdown of the carbon footprint. A version of this GHG emission model is also included in the Integrated Farm System Model (IFSM). This comprehensive whole-farm simulation model predicts GHG emissions along with farm performance, economics, and other environmental impacts including ammonia emission, nitrate leaching, and phosphorus runoff. IFSM is available for download at http://www.ars.usda.gov/Main/docs.htm?docid=8519. IFSM provides a research tool for comprehensive evaluation and comparison of current and novel production strategies.