Assessing Cropland Greenhouse Gas Emissions with Comet-Farm.

COMET-Farm is an integrated web-based, whole-farm/ranch decision support tool developed to aid farmers, ranchers, agricultural producers, land managers, and conservationists in making on-farm decisions regarding greenhouse gas emissions and carbon sequestration. COMET-Farm is a powerful greenhouse gas accounting tool allowing users to assess the greenhouse gas emissions from their current management practices as well as future management scenarios. Biomass and soil carbon; CO₂ emissions from liming, Urea fertilization and drained organic soils; CO from biomass burning; N₂O from soil, wetland rice cultivation, biomass burning and drained organic soils; and CH₄ from soil, wetland rice cultivation and biomass burning are accounted for in the tool. The DayCent simulation model in conjunction with the methods described in the USDA document, Quantifying Greenhouse Gas Fluxes in Agriculture and Forestry: Methods for Entity-Scale Inventory are used to estimate past, present and future emissions.  Agricultural soil management is the leading source of greenhouse gas emissions in the agricultural sector. Applying conservation practices can greatly reduce the amount of greenhouse gas released into the environment and aid in building and storing soil carbon.  COMET-Farm allows rapid assessment of conservation scenarios to aid in conservation planning.  To showcase the tools capabilities, real-world production systems are assessed showing how on-farm conservation practices influence the greenhouse gas flux in agricultural cropland systems. The results from various farming practices across the US will be presented.