CO2 Research.doc by babbian


									                                 CO2 Research
                                     February 6, 2005

Web Resources:
        Title: Carbon Dioxide In Greenhouses
        Division:      Agriculture and Rural
        History:       replaces OMAF Factsheet Carbon Dioxide in Greenhouses, Order No. 94-
        Written by: T.J Blom; W.A. Straver; F.J. Ingratta; Shalin Khosla - OMAF; Wayne
        Brown – OMAF

       “For the majority of greenhouse crops, net photosynthesis increases as CO2 levels
       increase from 340–1,000 ppm (parts per million). Most crops show that for any given
       level of photosynthetically active radiation (PAR), increasing the CO2 level to 1,000 ppm
       will increase the photosynthesis by about 50% over ambient CO2 levels.”
       “Ambient CO2 level in outside air is about 340 ppm by volume. All plants grow well at
       this level but as CO2 levels are raised by 1,000 ppm photosynthesis increases
       proportionately resulting in more sugars and carbohydrates available for plant growth.”

       Ziszka L H , Ghannoum O, Baker JT, Conroy J, Bunce JA, Kobayashi K, Okada M. A global perspective of ground
       level, `ambient' carbon dioxide for assessing the response of plants to atmospheric CO2. Glob. Ch. Biol., 7, 789-
       796 2001.

       Many experimental studies have shown that agricultural crops respond positively to elevated atmospheric CO2
       concentrations, with yields typically increasing 10-40% in response to a doubling of current levels (Kimball,
       1983). To this end, most recent controlled crop growth experiments have used constant CO2 concentrations, in
       the range 330-370 ppm, as representative of today’s ambient conditions. Yet a recent study (Ziszka et al., 2001)
       shows that CO2 concentrations at typical agricultural sites can be as high as 500 ppm at night, decreasing only
       gradually to 350 ppm during the day, with average daily values between 390 and 465 ppm. In their paper, Zizska
       et al. (2001) show that crop plants grown under these conditions accumulate biomass differently than when
       grown under the constant CO2 levels used in most controlled plant experiments. Their findings suggest that the
       currently projected response of field crops to future elevated CO2 concentrations may be overestimated.
        Article 2-3 Effective Use of co2
        “The Canadians discovered that adding C02 to plants at the seedling-rooted cutting stage
        - for about two weeks - produced two benefits: faster early growth and greater final crop
        yield, even without extra C02 during green growth or crop production!”
        Home Harvest Garden Supply, Inc.
        Article promoting their CO2 supplement. It indicates that plants do grow better with more
        CO2 but that CO2 levels drop near the center of a greenhouse in the winter.
        “Green plants convert carbon dioxide and water into food compounds, such as glucose,
        and oxygen. This process is called photosynthesis.

       The reaction of photosynthesis is as follows:
       6 CO2 + 6 H2O --> C6H12O6 + 6 O2

       Plants and animals, in turn, convert the food compounds by combining it with oxygen to
       release energy for growth and other life activities. This is the respiration process, the
       reverse of photosynthesis.

       The respiration reaction is as follows:
       C6H12O6 + 6 O2 --> 6 CO2 + 6 H2O

       Photosynthesis and respiration play an important role in the carbon cycle and are at
       equilibrium with one another.
       Photosynthesis dominates during the warmer part of the year and respiration dominates
       during the colder part of the year. However, both processes occur the entire year.
       Overall, then, carbon dioxide in the atmosphere decreases during the growing
       season and increases during the rest of the year.
       Because the seasons in the northern and southern hemispheres are opposite, carbon
       dioxide in the atmosphere is increasing in the north while decreasing in the south, and
        vice versa. The cycle is more clearly present in the northern hemisphere; because it has
        relatively more land mass and terrestrial vegetation. Oceans dominate the southern
        Open Roof Greenhouse by Roger Fox
        The issue of inadequate ventilation in greenhouses is a topical one in Australian
        horticulture. At one NSW nursery a fixed greenhouse roof has recently been replaced
        with two fully opening screens.

Peer Reviewed Articles:
*Altered night-time CO2 concentration affects the growth, physiology and biochemistry of soybean
Griffin, KL; Sims, DA; Seemann, JR
Source: Plant Cell and Environment; Jan., 1999; v.22, no.1, p.91-99

An inexpensive system for exposing plants in the field to elevated concentrations of CO[sub2].
By: Ashenden, T. W.; Baxter, R.; Rafarel, C. R.. Plant, Cell & Environment, Apr1992, Vol. 15
Issue 3, p365, 8p; DOI: 10.1111/1365-3040.ep8115311; (AN 8115311)

*Photosynthetic traits in wheat grown under decreased and increased CO2 concentration, and after transfer
to natural CO2 concentration
Ulman, P; Catsky, J; Pospisilova, J
Source: Biologia Plantarum (Prague); 2000; v.43, no.2, p.227-237

*Effects of elevated carbon dioxide, ozone and water availability on spring wheat growth
and yield, Håkan Pleijel, Johanna Gelang, Ebe Sild, Helena Danielsson, Suhaila Younis, Per-
Erik Karlsson, Göran Wallin, Lena Skärby, Gun Selldén
Physiologia Plantarum. Volume 108 Issue 1 Page 61 - January 2000

*Plant water relations at elevated CO2: Implications for water-limited environments
Wullschleger, SD; Tschaplinski, TJ; Norby, RJ
Source: Plant Cell and Environment; February, 2002; v.25, no.2, p.319-331

*Plant growth and competition at elevated CO2: On winners, losers and functional groups.
Poorter, H; Navas, ML
Source: New Phytologist; February 2003; v.157, no.2, p.175-198
*Effects of elevated CO2 on five plant-aphid interactions
Hughes, L; Bazzaz, FA
Source: Entomologia Experimentalis et Applicata; April, 2001; v.99, no.1, p.87-96

*Let the sunshine in
Roberts, WJ
Source: Resource: Engineering and Technology for Sustainable World; July 2001; v.8, no.7, p.7-8

Chlorophyll content of spring wheat flag leaves grown under elevated CO2 concentrations and other
environmental stresses within the 'ESPACE-wheat' project
Ommen, OE; Donnelly, A; Vanhoutvin, S; van Oijen, M; Manderscheid, R
Source: European Journal of Agronomy; April, 1999; v.10, no.3-4, p.197-203
                 “ Spring wheat cv. Minaret was grown in open-top chambers at four sites across
                 Europe. The effect of different treatments (CO2 enrichment, O3 fumigation,
                 drought stress and temperature) on the chlorophyll content of the flag leaf was
                 investigated using the MINOLTA SPAD-502 meter. Under optimum growth
                 conditions the maximum chlorophyll content, which was reached at anthesis, was
                 consistent among the sites ranging from 460 to 500 mg chlorophyll m−2. No
                 significant effect of elevated CO2 or O3 was observed at anthesis. Leaf
                 senescence, indicated by the chlorophyll breakdown after anthesis, was relatively
                 constant in the control chambers. Under control conditions, thermal time until
                 50% chlorophyll loss was reached was 600°C day. Elevated CO2 caused a faster
                 decline in chlorophyll content (thermal time until 50% chlorophyll loss was
                 reduced to 500–580°C day) indicating a faster rate of plant development at two
                 experimental sites. The effect of ozone on chlorophyll content depended on the
                 time and dose of O3 exposure. During grain filling, high O3 concentrations
                 induced premature senescence of the flag leaves (up to −130°C day). This
                 deleterious effect was mitigated by elevated CO2. Drought stress led to faster
                 chlorophyll breakdown irrespective of CO2 treatment.”

* Indicates a copy of this article is posted on basecamp

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