Dear All,
Angel is quite right in saying that there is considerable uncertainty
regarding the CO2 effect. However, I'm not sure that a simple on/off
approach is best. I think that we can do a better job of sampling the
uncertainty. I have a paper on this in the Royal Society proceedings
that Angel mentions.
Perhaps more relevantly this issue also contains Steve Long's paper, and
many other excellent papers. You can view the abstracts at
www.pubs.royalsoc.ac.uk/philtransb
If you email [log in to unmask] quoting reference TB1463 you may still
be able to order this special issue at the reduced price of 45 pounds
(usually it's 115 pounds).
Best wishes,
Andy
Ángel Utset Suastegui wrote:
>Models just use previous results regarding CO2 effects on crops. There are several published results of FACE experiments conducted in USA and Europe that I suggest you to review. These assessments comprise C4 and C3 crops. Some of them can be found in volume 10 of the European Journal of Agronomy (1999).
>I think that while other models might not take in account the fertilizer effects, DSSAT models do. I suggest you to review particularly the following paper:
>Tubiello, F.N., Ewert, F. 2002. Simulating the effects of elevated CO2 on crops: approaches and applications for climate change. European J. Agron. 18:57-74.
>However, there are some recent evidences that such positive effects might be overestimated. There was an interesting meeting in the Royal Society of London last year, "Food crops in a changing climate", where they conclude that:
>"Experiments on crops under realistic field conditions have shown that the beneficial 'fertilisation' effect of increased levels of atmospheric carbon dioxide (CO2) could be less than that previously estimated".
>The presentation in this regard was made by Professor Steve Long, University of Illinois at Urbana-Champaign, USA. He has some published papers concerning this.
>
>At the end, I (and perhaps you and many more) do not know exactly what to do concerning the CO2 effect!. Perhaps the best choice is to perform two simulations with DSSAT. The first considering the CO2 effect and a second simulation later ignoring it. Confident results must be somewhere in between!.
>
>Dr. Angel Utset
>Research Division
>ITACyL
>Carretera de Burgos, Km.119
>47071-VALLADOLID-SPAIN
>Telf. +34 983 410 436 Fax.+34 983 414 780
>[log in to unmask]
>
>
>-----Mensaje original-----
>De: DSSAT - Crop Models and Applications [mailto:[log in to unmask]] En nombre de Roberts, Michael
>Enviado el: jueves, 02 de marzo de 2006 16:39
>Para: [log in to unmask]
>Asunto: 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
>
>
--
Andrew Challinor, CGAM, Dept. of Meteorology,
University of Reading, Reading RG66BB, U.K.
http://www.met.rdg.ac.uk/~ajc
Tel (44) (0)118 3786016; Fax (44) (0)118 3788316
--
Andrew Challinor, CGAM, Dept. of Meteorology,
University of Reading, Reading RG66BB, U.K.
http://www.met.rdg.ac.uk/~ajc
Tel (44) (0)118 3786016; Fax (44) (0)118 3788316
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