Software / WinEPIC

WinEPIC is a production-risk management model designed to help agricultural practitioners optimize crop management and maximize production and profit, to identify limitations to crop yield, to assist growers with replant decisions, and to identify best management practices that minimize impact of agriculture on soil erosion and water quality. It is a windows-based application of EPIC (Environmental/Policy Integrated Climate model) originally developed by USDA-ARS that simulates the interaction of natural resources (soil, water, climate) and crop management practices to estimate impacts on harvested crop yield, soil properties, soil erosion, profitability, and nutrient/pesticide fate.

Download WinEPIC for EPIC v.0810 (June 2016)

WinEPIC operates under Windows® 98, 2000, and XP with 128 MB RAM and requires 250 to 500 MB of space on the hard drive for installation and operation. Information for basic model operation is organized in databases by agricultural region. The databases contain basic information for model operation, but the user can fully customize to simulate his/her conditions and needs. Databases can be constructed for most agricultural regions in the U.S.A. Some state databases are available on request from

Crop Management Simulations

  • Fertilization: N and P (mineral, manure)
  • Planting date, crop maturity, crop type, and rotation sequence
  • Cover crop and double cropping systems
  • Irrigation: sprinkler, furrow, flood, buried and surface drip
  • Plant population and row spacing
  • Tillage/residue management
  • Pesticide (economics and fate)

Special Features

  • Update/modify/create soils, weather, crop growth, and management to current conditions.
  • Performs direct comparisons of soil type/characteristics, cropping systems, management practices to identify best opportunities over- and within- cropping season
  • Information saved and sorted by Producer name, Soil, County, Weather Station, Cropping System, Farm, Field and Management Unit.
  • Control Table Editor to customize control parameters including years of simulation, beginning year of simulation, auto-irrigation trigger, auto-irrigation and fertilization limits among numerous other control parameters.
  • Yearly/monthly/daily data output to Access tables enabling manipulation of data.
  • Generates daily weather from monthly statistics if daily weather data is missing.
  • Stand-alone utility to download and update daily weather records to current day from the web or user collected/supplied daily records.
  • Performs farm level economic analyses.


  • Identify best management practices for site-specific climate and soil variation.
  • Identify production constraints and alternative practices to maximize yield, profit, and production efficiency.
  • Determine fertility/nutrient needs and nutrient and pesticide fate.
  • Identify the “Best Management Practices” for site-specific circumstances to minimize cropping impact on soil erosion, water quality, and runoff.
  • Determine El Nino/La Nina impacts on productivity and alternative production practices.
  • Perform economic and production risk assessments through probability analyses.

Databases Included

  • Weather: 40+ years of observed daily maximum and minimum temperature and precipitation and monthly statistics from selected National Weather Service Class 1 or coop weather sites to operate weather generator
  • All NRCS Soils 5, Management Unit Use Files by County
  • Pesticides, Fertilizers and Equipment
  • Management: sequential farming operations by cropping system: crop, tillage (conventional, reduced and no-till), and water application (irrigation versus dryland)
  • Crops simulated: U.S. field crops, forages, perennials, rangeland, sugarcane, and vegetables


  • Economics
  • Stresses
  • Crop Yield
  • Water Balance
  • Nutrient Balance
  • Non-point Losses
  • Pesticide Fate and Losses