Hello Andy,
   You can find a little more information about the root growth factor in
this publication:
      Ritchie, J.T., D.C. Godwin, and U. Singh. 1990. Soil and water inputs
for the IBSNAT crop models.
         p.31-46. In International Benchmark Sites Network for
Agrotechnology Transfer (IBSNAT) Project,
         Proceedings of the IBSNAT Symposium: Decision Support System for
Agrotechnology Transfer,
         Las Vegas, Nevada. 16-18 Oct. 1989. Part I: Symposium Proceedings.
Department of Agronomy and
         Soil Science, College of Tropical Agriculture and Human Resources,
University of Hawaii, Honolulu,
         Hawaii.
The information is a little old, but as far as I know it still applies.
Hope this helps.
Sincerely,
Richard

At 10:13 AM 7/28/99 -1000, you wrote:
>I am running DSSAT version 3.5 and am interested in finding out more
information about the Root growth factor  as described on Page 46 of Volume
2 in "DSSAT Version 3" manual.  I would like to know how to approximate
this factor for the Soil.sol file and what the values from 0.0 to 1.0.
>
>Can you tell me where I can locate this information?
>
>I would be much obliged!
>
>Andy Bootsma
>
>
>
>********************************************************
>Andrew Bootsma
>Agriculture and Agri-Food Canada
>Eastern Cereal and Oilseed Research Centre
>K.W. Neatby Bldg., Rm 4129B
>960 Carling Ave.
>Ottawa, ON  CANADA  K1A 0C6
>
>Tel:  (613) 759-1526
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>Homepage: http://res.agr.ca/ecorc/staff/boot-a.htm
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