Dear Octavio,

The pasture model of DSSAT was build in the structure of the soybean model
by defining a new set of generic coefficients: the species, cultivar and
ecotype files (*.SPE, *.CUL, *.ECO) in the DSSAT subdirectory GENOTYPE. It
is thus not just any pasture, but the specific species Bahía grass with the
cultivar and ecotype of unknown name as given in the G0GRO980.CUL and
G0GRO980.ECO files. It may seem a bit funny to grow a grass in a soybean
model, but this model is the generic CROPGRO, which can be used for many
crops and which DSSAT also uses for tomato.

A few years ago I did the same for Brachiaria decumbens, an important grass
of improved pastures in the tropics. The results of the calibration and
validation for this grass were presented in:
Giraldo L.M., Lizcano L.J., Gijsman A.J., Rivera B., Franco L.H. 1998
Adaptación del modelo DSSAT para simular la producción del Brachiaria
decumbens. (Adapting the DSSAT model for simulating the production of
Brachiaria decumbens). Pasturas Tropicales 20:2-12.

The same work was later also presented at the Third International Symposium
on Systems Approaches for Agricultural Development (SAAD-III) in Lima, Peru,
from which an English-language version of the article resulted by the same
authors. If you are interested, I have this available as PDF file.

The next version of DSSAT, to be released later this year, will have both
Bahía and Brachiaria.


Arjan Gijsman
Univ. Florida / Centro Internacional de Agricultura Tropical (CIAT)



-----Original Message-----
From: Octavio A. Castelán-Ortega [mailto:[log in to unmask]]
Sent: Tuesday, April 09, 2002 3:13 PM
To: [log in to unmask]
Subject: Pasture Model


Dear All
I am just starting to use the DSSATV3.1 pasture model, so I would like
to know what sore of data I need to calibrate the model and I would also
appreciate very much if you can tell which papers or other relevant
information I need to read to get familiar with it.
Thank you very much
Dr. Octavio Castelán
CICA-UAEM