Michael,

See the following links for recent evidence on CO2 fertilization effects on
corn.

http://www.plantphysiol.org/cgi/content/abstract/140/2/779
http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-2486.2006.01110.x

These papers agree with the idea that the high CO2 effect on photosynthesis,
growth, development, and therefore on yield would be minimal in C4 corn in the
absence of water stress and suggest that most significant changes occur in
reduction of water use derived from stomatal responses to high CO2. Hope this
helps.

Soo


Soo-Hyung Kim

USDA-ARS, Plant Sciences Institute
Crop Systems and Global Change Laboratory
Bldg. 001 Room 342, BARC-West
10300 Baltimore Avenue
Beltsville, MD 20705-2350, USA

Tel: (301) 504-5343
Fax: (301) 504-5823
e-mail: [log in to unmask]


-----Original Message-----
From: DSSAT - Crop Models and Applications [mailto:[log in to unmask]] On
Behalf Of Roberts, Michael
Sent: Thursday, March 02, 2006 10:39 AM
To: [log in to unmask]
Subject: The latest evidence on CO2 fertilization for corn, soybeans, and
cotton

Dear listserv members,

I understand this forum mainly pertains to the DSSAT simulation software
and so this question may be a little off topic.  But I figured the
members would likely be very knowledgeable.

Can some one point me toward the latest evidence on the likely effects
of CO2 fertilization on corn, soybean, and cotton yields?  I have found
a few papers suggesting fairly large positive effects, and most of these
employ simulation models.  I have also seen papers suggesting that while
yields may increase, caloric content increases much less.  I'm
interested in the most compelling evidence and how this is folded into
the simulation models.  No need to spell out the details, but citations
would be greatly appreciated.

Many thanks,

Michael J. Roberts
USDA Economic Research Service
Washington, DC 20036
202-694-5557