1. General Model Information
Name: Sigma +
Main medium: terrestrial
Main subject: biogeochemistry
Organization level: ecosystem
Type of model: partial differential equations (2D), ordinary differential equations
Keywords: crop, cotton growth, plant-soil-atmospheric interactions, management
Western Regional Research Center
USDA 800 Buchanan Street
Albany, CA 94710
Fax : 510-559-5798
Hal Lemmon and Ning Chuk
Sigma + is a cotton growth model that simulates plant-soil-atmospheric
interactions for the purposes of examining potential effects of climate change
and providing management information to cotton farmers. The model uses 2DSOIL,
a two-dimensional root-soils model developed at the ARS Salinity Laboratory.
This model is part of a larger effort to develop
new crop models and to develop graphical user interfaces (GUI) for existing
crop growth models
for the purposes of interfacing them with
soils models. The models can be used for the purposes of management of
agricultural chemicals and examining the possible effects of climate change on
Author of the abstract:
II. Technical Information
Operating System(s): Model requires 4 minutes to simulate one season on a SunSparcStation; 30 minutes on a 486, 33 mhz PC
Programming Language(s): C++ for all but the soils models. FORTRAN for the soils models.
III. Mathematical Information
Variety data, weather data, soil parameters, irrigationschedule, fertilization schedule. Approximately 150 plots showing the growth of the cotton plants and the
Approximately 150 plots showing the growth of the cotton plants and theevolution of a large number of parameters.
Temporal Scale: From emergence to harvest.
Spatial Scale: A cotton field.
V. Further information in the World-Wide-Web
VI. Additional remarks
This model is potentially valuable to the climate change research becauseit interfaces known crop growth models with a soils dynamics model. Inaddition, the model is designed to examine the effects of chemical inputson water pollution.
Last review of this document by: T. Gabele: 08. 07. 1997 -
Status of the document:
last modified by
Tobias Gabele Wed Aug 21 21:44:49 CEST 2002