Corn Yield Comparison BetweenEPIC-View Simulated Yield And

Observed Yield Monitor Data

by

Chad M. Boshart

Oklahoma State University

Objectives

1. Compile data to be used in model runs.

2. Calibrate EPIC-View simulated yield with observed yield results from 2000.

3. Validate EPIC-View by using the 2001 observed yield results.

EPIC-View

EPIC(Environmental

Policy Integrated Climate)

ArcView GIS

Graphical User Interface

EPIC formerly Erosion Productivity Impact Calculator

Created in the early 1980’s by scientists at The Texas Agricultural Experiment Station Blackland Research Center in Temple, Texas.

EPIC is a DOS based program designed to:•Simulate biophysical processes simultaneously•Simulate cropping systems for hundreds of years•Applicable to a wide range of soils, climates and crops•Efficient, convenient to use and capable of simulating management effects on soil erosion and productivity.

EPICComponents:

WeatherHydrologyErosionNutrient CyclingPesticide RateSoil TemperatureTillageCrop GrowthCrop and Soil ManagementEconomics

Applications

•Crop Productivity•Soil Degradation•Input Levels and Management Practices•Response to Climates and Soils•Climate Change

(Williams, 1989)

UTIL screen with EPIC data

UTILUniversal Text Integration LanguageData file editor that was developed to help users build datasets for large computer models and other data intensive programs.

- Dumesnil 1993

Data Files (or dat)Data supplied by the user

EPIC

Crop

Misc.

Herbicide

Pesticide

TillageGraphics

Multi-Run

Output

Daily Weathe

r

UTIL and Dat

Data files have a specific format with a set range. The UTIL file organizes the user specified information from the Data files into one file to be used by EPIC-View.

ArcView• Created by ESRI (Environmental Systems

Research Institute) in 1992.• Founded and owned by Jack and Laura

Dangermond.• Based out of Redlands, California.• Gives ability to work with data geographically.• Display maps from tables.• Identify trends in the data.• Easy to integrate data.

Study Area: Garfield County, OK

List of Attributes in Megasurface Table

Where the data came from?

• Seed Rate Populations• Tillage Operations• Fertilizer Applications• Pesticide Applications• Irrigation • Pest Management• Yield / Harvest

Management Data

• Hydrology• Soils Classification• Soil-Specific Parameters• Slope and Aspect• Fertility (Variability)• Etc...

Resource Data

• Precipitation• Soil Temperature• Air Temperature (min & max)• Humidity• Wind Speed and Direction

Meteorological Data

• County and City Boundaries• Public Land Survey• Digital Elevation Model• Generalized Soils

Regional Data

Yield Points

Yield Surface

Starting Up

Preferences and Attributes

Environmental Data

Parameters

More Preferences

Field Operations

Output

Estimated Yield Result

2000 and 2001 Yield Points

Estimated vs. 2000 Yield

Estimated vs. 2001 Yield

Slope

Soil Types

Soil type vs. Yield

Slope vs. Estimated Yield

Conclusions

Very little variability in the estimated yield.The results show that the estimated yield appears to be similar to slope and soil type.Could be improved upon by adding the soil nutrient levels.

Questions???