Hello from Gainesville,
 
As presently configured, when you run the crop sequencing option, you may
have minor effects of water carryover (or available soil N) caused by
previous crops and fallow period on the next simulated soybean crop.  Other
than that there are no rotation effects of previous crops on soybean yields.
 
I realize that there really are "rotational benefits" caused by lessening
of diseases, nematodes, and allepathic effects, but none of the crop models
presently do this to the best of my knowledge.  If you can give me the
"adjustments" to make, we can code it or you can do your own adjustments.
 
Lastly, the model really does predict everything on a dry matter basis,
including seed yield.  We have, however, ignored the adjustment to 13%
moisture for seed yield.  This is a question that Jim, Gerrit, Bill
Batchelor, and I need to discuss.
 
Best regards,
Ken Boote
 
 
 
At 11:20 AM 9/23/97 -0600, you wrote:
>Hi,
>
>I am working as a postdoc at NCAR and I am studying the impacts of
>climate change on agriculture at SE USA. For the time being I am working
>on the validation of CROPGRO (from DSSAT)for soybean. Could anyone out
>there inform me about the differences that previous crops (corn, fallow,
>sorghum, potato, fallow, cotton) make for my simulations. Also, my
>harvest yields are reported at 13% moisture level. Is this the normal
>level or should I adjust the yields estimated with the crop model.
>
>Any ideas on my requests would be really appreciated.
>
>Thank you in advance.
>
>Theodoros
>--
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>Theodoros Mavromatis                           tel: +303-497-8127
>National Center for Atmospheric Research       fax: +303-497-8125
>ESIG, P.O. Box 3000
>Boulder, Colorado, 80307
>USA
>