Jean,

Soil depth will have a major effect on final simulated yields for the DSSAT
models.  60-cm is much too shallow.  We typically use soil profiles that go
to 180 cm, unless you absolutely know that there is only bedrock below 60
cm.  Both the soil depth and depth extent of the rooting preference
function (in soil files) makes a big difference, particularly if you will
evaluate effects of future climate change (warmer).  I liked Andy Bootsma's
comments.  There are people in AgCanada who will have some knowledge of the
information you need.

Ken Boote


At 03:48 PM 11/26/01 -0500, you wrote:
>Dear DSSAT users,
>
>I'm using the DSSAT suit of crop models to evaluate the impacts of
>CO2-induced climate change on agricultural yields in the province of Quebec,
>Canada.
>
>because I'm trying to evaluate the impacts on crop yields for all of
>Quebec's agricultural region, I'm not working on some specific sites. As
>such, I have very general soil data for every region.
>
>My problem is that the only analysis of the soils caracteristics that was
>done for the whole of quebec's agricultural territory did not go deeper than
>60cm. Hence, my soil profiles contain only 3 layers and are 60cm deep.
>
>I wanted to know if that would affect the final simulated yields in a
>significant manner and, if so, if there is any way to solve this problem?
>
>thank you for your help,
>Sincerely,
>
>Jean-Philippe Brassard
>Departement de Geographie
>Universite de Montreal
>
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