Modeling plant competition with the GAPS object-oriented dynamic simulation model

David G. Rossiter
Susan J. Riha
Agronomy Journal 91 (5): 773-783 1999
Copyright © 1999 American Society of Agronomy, Inc.


Modeling inter-species competition is a natural application for dynamic simulation models of agricultural systems. We extended a dynamic simulation model of the soil-plant-atmosphere system, GAPS, to include the case where multiple plant species are growing in competition. The competition model is implemented as an object hierarchy which exchanges information with the existing crop model hierarchy by means of access procedures. Existing crop models in the object hierarchy required minimal change in order to support the competition model. Two competition models were implemented: modified ALMANAC and winner-takes-all . GAPS is written in Turbo Pascal 5.5 (MS-DOS) and Delphi (Windows 95) using the object-oriented programming constructs of those languages. The modified ALMANAC model requires that crop models simulate leaf area index, single-crop light interception, and canopy height, from which information it partitions solar radiation to the several crops growing in competition.


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Author: David G. Rossiter, E-mail dgr2 (at)


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