Field- And Farm-Scale Assessment Of Soil Greenhouse Gas Mitigation Using Comet-Farm

Achieving more sustainable production of food, fiber and energy and reducing environmental burdens from agricultural systems is a global challenge. Meeting this challenge will create new opportunities for producers to provide a broader range of ecosystem services, including reducing greenhouse gas emissions (and sequestering more carbon) in their production systems. To meet these new objectives, land managers will need new decision tools and performance metrics.The COMET-Farm system was designed to fill this need by incorporating state-of-the-art greenhouse gas quantification methods into a web-based tool that can be used by farmers, ranchers, land managers and others. The system is capable of doing a full greenhouse gas assessment for CO2, CH4, and N2O, from all major on-farm emission sources (and CO2 removal into biomass and soil sinks), including land management of annual and perennial crops, pasture, range and agroforestry systems, as well as emissions from livestock and on-farm energy use. The system uses a fully spatial mapping and menu-driven graphical user interface (GUI) to facilitate data entry and evaluation of user-defined conservation practices.In this paper we provide an overview of the system and a description of the user interface and integrated databases in the system. We follow this with a brief description of the models and data requirements for the major emission source categories in the system. We illustrate the application of the system using examples of emission reductions from adoption of different conservation management practices and discuss how the tool can help meet needs for different policy-and market-driven greenhouse gas reduction efforts.