1. General Model Information


Acronym: SORKAM

Main medium: terrestrial
Main subject: biogeochemistry
Organization level: ecosystem
Type of model: compartment model
Main application:
Keywords: crop, sorghum, growth, management


Dr. R. L. Vanderlip
Department of Agronomy
Kansas State University
Throckmorton Hall Manhattan, KS66506Phone: 913 532-7249
Fax : 913 532-6049
email: vanderrl@ksuvm.edu



SORKAM is an IBSNAT model that simulates daily growth of grain sorghum. The model calculates emergence and dry matter production based on daily maximum and minimum temperatures, precipitation and intercepted solar radiation. Solar radiation can be estimated using a weather simulator, such as WGEN .

Other data inputs include: available water capacity, initial water content, planting date, maturity of hybrid, and row spacing. Latitude and altitude are also required. Various management parameters are also required. The model is currently being modified by the developer at Kansas State University to account for moisture and nutritional stress.

Author of the abstract:


II. Technical Information

II.1 Executables:

Operating System(s): Portable to most platforms

II.2 Source-code:

Programming Language(s): FORTRAN

II.3 Manuals:

II.4 Data:

III. Mathematical Information

III.1 Mathematics

III.2 Quantities

Model requires daily maximum/ minimum temperature,

III.2.1 Input

Model requires daily maximum/ minimum temperature,rainfall, and solar radiation. Or solar radiation can be calculated according to WGEN method ifsolar radiation is not available. Available water capacity and initial water content, as well as, stageone and stage two evaporation coefficients are required. SCS runoff curve number is used tocompute runoff. Specific planting information for date of planting, plant population, maturity ofhybrid, and row spacing are required. Latitude and altitude of the site are also required.

Model Input Data Source: Sources of input data are standard climate files, SCS soilsinformation, and user provided planting information. Output can either be on a daily time-step or multiple thereof basis or a

III.2.2 Output

Output can either be on a daily time-step or multiple thereof basis or aseason summary. Detailed output includes weights of each plant part, leaf area index, and stressfactors for temperature and moisture. Summary output includes dates of major phenologicalstages, grain yield and yield components and total water use.

Temporal Scale: One day.

Spatial Scale: The area occupied by a single plant and then the weights are computed on an areabasis (ha).

IV. References

Rosenthal, W.D., R.L. Vanderlip, B.S. Jackson, and G.F. Arkin. 1989.SORKAM: A Grain Sorghum Crop Growth Model, TAES, Computer Software DocumentationSeries, MP 16-69, Texas A & M University, College Station, TX.

V. Further information in the World-Wide-Web

VI. Additional remarks

Sorghum is one of the top five cash crops grown in the United States. Knowledge of its growth dynamics given potential changes in climate, soil characteristics (such as soils moisture) and changes in management will beimportant to sorghum farmers.
Last review of this document by: T. Gabele: 08. 07. 1997 -
Status of the document:
last modified by Tobias Gabele Wed Aug 21 21:44:50 CEST 2002

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