Kelsey;

DSSAT v4.02 does not include a true tillage model.  A tillage event triggers incorporation of organic matter (100% as you have observed) and no modification of soil properties.  The upcoming DSSAT v4.5 will include a true tillage model that incorporates surface residues at a specified mixing percent, modifies bulk density and drainage characteristics and mixes all soil constituents.

Regards,
Cheryl

-----Original Message-----
From: DSSAT - Crop Models and Applications [mailto:[log in to unmask]] On Behalf Of Brandt, Kelsey
Sent: Tuesday, April 08, 2008 6:02 PM
To: [log in to unmask]
Subject: Tillage Model

Hi all,



I am using DSSAT v2.0.2.0, and when I include several tillage operations in one year as part of a sequence file run or have a tillage depth of greater than 0 cm, all the surface residue is buried by the model.  Generally speaking in Canadian agriculture, most of the residue remains on the surface after tillage unless an implement that turns over the soil is used.  Am I doing something wrong in my sequence files, or is the tillage model not working in this version of the model?



Regards,



Kelsey Brandt
Agriculture and Agri-Food Canada/Agriculture et Agroalimentaire Canada
Telephone/Téléphone: 306-778-3107
Facsimile/Télécopieur: 306-788-3188

P.O. Box 1030, # 1 Airport Road

Swift Current, Saskatchewan, Canada
S9H 3X2

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