1. General Model Information

Name: Decision Support System for Agrotechnology Transfer Version 3.5

Acronym: DSSAT

Main medium: terrestrial
Main subject: biogeochemistry, agriculture
Organization level: ecosystem
Type of model: not specified
Main application: decision support/expert system, research, education
Keywords: environment, agriculture, agroecosystem, agricultural management effects, rotation, yield, crop growth, corn, bean, soybean, peanut, decision support system, modellling system, multiple growth models, Ceres, Cropgro, database


International Consortium for Agricultural Systems Applications
2440 Campus Rd., Box 527
Honolulu, HI 96822, USA

DSSAT Crop Models:
Dr. Gerrit Hoogenboom
Professor &
Coordinator of Research, Extension and Instruction
Department of Biological and Agricultural Engineering
The University of Georgia
165 Gordon Futral Court
Griffin, Georgia 30223-1797, USA

Phone: ICASA: +1-808-956-7531     G. Hoogenboom: +1-770-229-3438
Fax:      ICASA: +1-808-956-2711     G. Hoogenboom: +1-770-228-7218
email: ICASA       Gerrit Hoogenboom
Homepage: International Consortium for Agricultural Systems Applications          Gerrit. Hoogenboom



The goal of the International Benchmark Sites Network for Agrotechnology Transfer (IBSNAT) Project is to accelerate the flow of agrotechnology and increase the success rate of technology transfer from agricultural research centers to farmers' fields. To do this, IBSNAT has developed computer software which helps match crop requirements to land characteristics using crop simulation models, data bases, and strategy evaluation programs. The resulting system is called the Decision Support System for Agrotechnology Transfer (DSSAT). DSSAT provides easy access to data bases and crop models so that the user may "test" on screen the performance of new cultivars, sites, or manag ement practices. This system allows user to screen new technology packages, such as a new cultivar or fertilizer management strategy, whithout spending excess time on expensive, time consuming field trials. By simulating outcomes of strategies on the computer screen, user can ask "what if" questions and explore the options on screen. Sustainable agriculture requires tools that enable decision makers to explore the future. A decsion support system must help users make choices today that result in desired outcomes, not only next year, but 10, 25, and 50 or more years into the future.

DSSAT was designed primarily for user groups in agriculture, but owing to its break with traditionaly ways of diagnosing and prescribing solutions, it has been adopted by other types of users. The emergence of issues which require assessment of conditions not in the past or present, but in the future calls for the systems approach to problem solving encompassed by DSSAT, which includes:

DSSAT is comprised of the following components:

  1. a Data Base Management System (DBMS) to enter, store, and retrieve the "minimum data set" needed to validate, list and use the crop models to provide outcomes to alternative management input
  2. a set of validated crop models
  3. an application program for analyzing and displaying outcomes of long-term simulated agronomic experiments.

The following crop models are currently accessible under the DSSAT shell. They include:

All crops share a common input-output format, and are similar in level of detail. They operate on a daily time step, and are based on an understanding of biophysical processes.

These models are process oriented, designed to have global applications, and work independent of location, season, crop cultivar, and management system. The models simulate the effects of weather, soil water, genotype, and soil and crop nitrogene dynamics on crop growth and yield.

The Data Base Management System (DBMS) in DSSAT is used to organize and store the Minimum Data Set (MDS). The MDS is the minimum data required to run DSSAT's crop models, and has become an international standard data set for model calibration and validation. The DBMS provides easy access to four data bases.

The Strategie Evaluation Program in DSSAT allows users to evaluate the merits of simulated strategies and identify the best one. The program uses cumulative probabilty functions to develop and select the strategy with the preferred mean and variability characteristics. With this program users can determine the effectiveness of crop management stragegies, the economic return of a new cultivar, or the suitability of a site for a specific crop. Using weather generators programs which generate coefficients from historical weather data, DSSAT can simulate the growth and development of a crop for up to 50 consecutive years. DSSAT allows up to 15 combinations of options to be simulated in a single experiment, generating in a few hours, amounts of data that have traditionally required an agronomist's lifetime of work.

Source of abstract information (partially): DSSAT Information page, IBSNAT, 1998.
Further information now at ICASA - DSSAT: http://www.icasa.net/dssat/index.html
Actual version of DSSAT: 4.0

II. Technical Information

II.1 Executables:

Operating System(s): DSSAT v3.5:
Any 486 or better IBM Personal Computer or compatible microcomputer with:

DSSAT v3.5 is distributed by the International Consortium for Agricultural Systems Applications (ICASA), Honolulu.
How to order:

II.2 Source-code:

Programming Language(s): Components of software are written in FORTRAN (crop models), C (shell), Pascal (graphics), DBase (database), and Basic (strategy and risk management programs)

II.3 Manuals:

II.4 Data:

III. Mathematical Information

III.1 Mathematics

III.2 Quantities

III.2.1 Input

View Input data requirements of DSSAT in comparison to other Soil Organic Matter related models:
These seven tables can be downloaded in Postscript Format

III.2.2 Output

View output data of DSSAT in comparison to other SOM - related models:

IV. References

Jones, C.A. and J.R. Kiniry. 1986.
CERES-Maize: A simulation model of maize growth and development. Texas A&M University Press, College Station.
Jones, J.W., K.J. Mishoe, G.G.Wilkerson, and S.S. Jagtap. 1986.
SOYGRO v. 5.3: Soybean crop growth and yield model,IBSNAT version. Technical documentation, University of Florida, Gainesville.
Carlos Pampulim Caldeira, Pedro Aguiar Pinto 1998, Linking DSSAT V3 to a relational database: the AGROSYS--DSSAT interface, Computers And Electronics In Agriculture (21)1 (1998) pp. 69

V. Further information in the World-Wide-Web

VI. Additional remarks

DSSAT mailing-list:
This mode of communication will allow each user to shareconcerns, successes, messages, and thoughts related to DSSAT and itsapplication. Additionally, information on updates and modifications willbe announced here as well as through conventional means.

Dr. Hoogenboom will serve as "caretaker" of the listserver.
Last review of this document by: T. Gabele: 23. 08. 1998, Juergen Bierwirth Mon Sep 25 16:54:43 CEST 2000

Status of the document:
last modified by Joachim Benz Fri Apr 20 15:37:02 CEST 2007

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