Agroecosystem Modeling and Decision Support for California's Soil Health Initiative.

The COMET-Farm system was developed as a state-of-the-art, web-based quantification and decision support tool for entity scale greenhouse gas (GHG) inventory, assessment and planning. The system does a full GHG inventory of all land use related sources and sinks, for biomass and soil C stocks and CO₂, N₂O and CH₄ fluxes from land management, livestock and energy use, at the scale of an individual farm. More than 20 empirical models as well as the DayCent process-based ecosystem model are used for C stock and GHG flux estimates. A user-friendly interface and embedded spatial and non-spatial databases make the system usable to non-specialists. In California, a large number of specialty crops, many of which are uncommon or absent from other parts of the US, are grown. These tree, fruit and vegetable crops represent a large part of the economic returns from agriculture in the state. We will present recent work on data synthesis and model development done to include these specialty crops within the COMET-Farm system. COMET-Planner is another tool derived from COMET-Farm, that provides regionally-representative estimates for GHG emission reductions from implementation of USDA/NRCS prescribed conservation practices. We describe methods and results for the deriving the COMET-Planner estimates of GHG reductions with implementation of conservation practices by participant in the Healthy Soils Initiative in California.