Community Modeling and Analysis System


Generate fertilizer application input for CMAQ bi-directional NH3 modeling

The Fertilizer Emission Scenario Tool for CMAQ (FEST-C) system is used to simulate daily fertilizer application information using the Environmental Policy Integrated Climate (EPIC) model for a defined CMAQ domain. This EPIC output information is a required input for CMAQ bi-directional NH3 modeling. The FEST-C contains two major components - a Java-based interface and EPIC modeling system. The FEST-C interface integrates the WRF/CMAQ with EPIC through the current release of the Spatial Allocator (SA v4.3.1) Raster Tools system. The interface contains 13 sub-interface tools which guide users through the EPIC simulations for CMAQ. The FEST-C system can be used in assessing not only the impacts of agricultural fertilization and management practices on the air quality (NH3) and climate (N2O), but also the impacts of meteorology/climate and air quality (N deposition) on crop yield, soil erosion and overall nitrogen, carbon and phosphorus biogeochemical status of the agricultural ecosystem.


Java-based FEST-C interface with 13 sub-interface tools to:

  • Build the input database of 21 crops for EPIC model simulations for a given CMAQ domain
  • Simulate daily fertilizer application information based entirely on simulated plant demand in response to local soil and weather conditions using EPIC,
  • Extract EPIC daily output for CMAQ bi-directional NH3 modeling, and
  • Visualize the simulation results spatially over the modeling domin.

EPIC Modeling system including:

  • EPIC model version 0509 from Texas A&M University (TAMU), modified by EPA to meet CMAQ input requirements,
  • Utility programs to build EPIC input data sets for CMAQ domain grid cells,
  • Common data sets (e.g. weather station climate statistic files and built soil data files) included in the EPIC modeling,
  • Scenarios which contain a test case and to store users' application scenarios, and
  • Documentation of the EPIC Modeling System for CMAQ 12km Grids in the FEST-C.


  • Follow the documentation for installation
  • FEST-C works for domains at different resolutions and in any of the four WRF projection coordinate systems - longitude/latitude, Lambert Conformal Conic, Universal Polar Stereographic, and Mercator

Updates in Version 1.3

  • Added additional output for bare land fraction and soil moisture
  • Added new feature which transfers beld4 file to ioapi format in the beld4 generation utilities
  • Added 2011 crop fraction for US and Canada for beld4 generation
  • Adjusted crop input parameters to improve yield evaluation in comparison to observations
  • Reduced number of output variables from EPIC2CMAQ
  • Bug fixes include elevation error, parameter inconsistencies, and EPIC2CMAQ daily extraction

Latest Version: FEST-C version 1.3



Hands-on FEST-C training will become available to the community in the near future.


Online Resources

  • Cooter et al. 2010: Estimation of NH3 bi-directional flux from managed agricultural soils, Atmos. Envi.
  • Ran et al. 2011: Development of an Agricultural Fertilizer Modeling System for Bi-directional Ammonia Fluxes in the CMAQ Model, 31th ITM paper.
  • Cooter et al. 2012: Linking agricultural crop management and air quality models for regional to national-scale nitrogen assessments, Biogeosciences.
  • Pleim et al. 2013: Development and evaluation of an ammonia bidirectional flux parameterization for air quality models, JGR-Atmosphere.
  • Bash et al. 2013: Evaluation of a regional air-quality model with bidirectional NH3 exchange coupled to an agroecosystem model, Biogeosciences.
  • 2013 Talk by Cooter et al.: FEST-C for Bi-directional CMAQ: Update
  • 2016 Talk by Cooter et al.: Enhancements to an Agriculture-land Modeling System - FEST-C and Its Applications

Previous Documentation

System Requirements

O/S Linux 64-bit x86
Software Spatial Allocator, VERDI
Compilers Intel Fortran for EPIC, GCC for SA Raster Tools


History of FEST-C

  • FEST-C V1.3 (06/30/2017) - Updated release
  • FEST-C V1.2 (05/31/2016) - Updated release
  • FEST-C V1.2 (02/09/2016) - Updated release
  • FEST-C V1.2 (09/30/2015) - Updated release
  • FEST-C V1.1 (05/30/2014) - Updated release
  • FEST-C V1.0 (10/25/2013) - First release

The development of the system has been funded by the EPA. The creation of the FEST-C interface and EPIC application was driven by the 2012 release of the bi-directional NH3 option for CMAQ. While there are other EPIC model user interfaces, FEST-C has been specifically designed to require minimal user inputs and to produce bi-directional CMAQ-ready output files for any CMAQ domain and grid cell resolution for which MCIP data is available.