Precision Farming - The Epic Model

The Environmental Policy Integrated Climate (EPIC) Model is a soil/crop model composed of several simulation components for weather, hydrology, nutrient cycling, pesticide fate, tillage, crop growth, soil erosion, crop and soil management and economics. The objective of this study was to evaluate the EPIC model on a variable landscape site specific management basis and to develop a computer-based tool that would integrate the EPIC model with the GRASS-GIS. A research project was initiated using EPIC to study the development of optimal agronomic management on a site-specific basis. Crop yields were monitored during 1994 and 1995 at four sites in Alberta using a high-precision 3-D Differential GPS. The EPIC model was used on a sub-field, site-specific basis using soil profile information for various landscape transects, agronomic management and daily climatic data. The crop growth routines of this model were

South Central ALBERTA: 1995 EPIC predicted wheat yield map at a site compared against two years of yield maps obtained from each field. The GISSMO interface provided an effective means of managing the various data layers for a field to utilize the EPIC model for each unique landscape-management polygon.

Relation between predicted and measured grain yield, using EPIC for all crops, fertilizer rates, etc.

This study showed that the EPIC model can function as a good predictor of crop yields in Alberta using Canadian crop parameters, local station weather data and, site-specific soil investigations. The potential benefit of using an integrated model is that other features of the model can then be used with little additional effort which may be very appealing for wide spread use in the agriculture industry. Models for nitrate and pesticide leaching, erosion and tillage are more likely to be used if they come as part of an agronomic model that can be used for prescription mapping and risk assessment. A reliable model could also be used to test various management practices, climatic conditions and soil conditions on crop yields and soil conservation. Considerable work is still needed but the potential use of a model for site-specific farming is to provide a very powerful tool for farmers and researchers.

Contact: Tom Goddard, Len Kryzanowski, Karen Cannon, Alberta Agriculture, Food and Rural Development #206, 7000 - 113 St. Edmonton, AB Canada T6H 5T6 phone: 403-422-6530 or 403-427-6361 fax: 403-422-0474 or 403-427-1439 goddard@gpu.srv.ualberta.ca, Len. Kryzanowski@mailer.agric.gov.ab.ca, cannon@agric.gov.ab.ca