"An understanding of processes"


Emission factors are commonly used to quantify the release of carbon and nitrogen from agriculture operations to the air, soil, and water. These factors over-simplify the systems and can result in emission totals that are significantly over- or under-estimated. The uncertainties introduced using emission factors can be reduced through the use of process models. These track the interactions amongst several influencing factors at various stages of crop development to assess strategies for decreasing carbon and nitrogen emissions. Enviro-Geo moves beyond the emission factor approach by developing tools that model the complexity of the systems for improved emission assessments.

Enviro-Geo uses an internationally recognized and respected nutrient cycling model known as DeNitrification-DeComposition (DNDC) as the core processor in its suite of agro-forestry modeling applications (see graphic below). Changsheng Li, the developer of DNDC, is a member of Enviro-Geo’s team of trusted collaborators. DNDC has been used for national and regional carbon and nitrogen inventories worldwide, as has been documented in over 50 peer-reviewed journal articles. Some of the benefits of adopting DNDC-based tools for impact assessment analyses include:
  • ability to run at two spatial scales – both individual farm or region/watershed
  • model a range of past, present, and future climate scenarios
  • model a wide range of crop and forest types and management alternatives
  • can model the full complement of nitrogen and carbon species
  • includes uncertainty analyses in all of its outputs

This powerful tool allows land managers to be proactive and assess the potential emissions under various management and climate scenarios, without having to actually implement the management change before understanding its impact. Specific focus areas for our model-based tools include:
  • Water Quality – quantification and mitigation of nitrate loading, including leaching to the groundwater and runoff to lakes and rivers

View a schematic of the DNDC model structure, showing the interactions amongst the six sub-models, ecological drivers, and soil environmental factors. A more detailed model description can be obtained at the DNDC website.