[Effects of CO2 enrichment, nitrogen and water on photosynthesis, evapotranspiration and water use efficiency of spring wheat].
Spring wheat (Triticum aestivum L.) was treated with 2 atmospheric CO2 concentrations (350 and 700 mumol.mol-1), 2 levels of soil moisture (wet and drought), and 5 levels of nitrogen fertilizer (0, 50, 100, 150, 200 mg.kg-1 soil). The results showed that elevated atmospheric CO2 increased photosynthetic rate more in drought than in wet treatment. Photosynthetic rate increased with the increase of nitrogen fertilizer. Stomatal conductance decreased with CO2 enrichment, which was more in drought than in wet treatment. CO2 enrichment decreased more evapotranspiration in drought than in wet treatment. The decrease was more apparent with no fertilization. CO2 enrichment increased more leaf water use efficiency in drought than in wet treatment. Canopy WUE increased with CO2 enrichment and N fertilization. Thus, the increase in photosynthesis and the reduction in evapotranspiration due to elevated CO2 can ameliorate the negative effects of drought, and increase wheat resistance to water stress.
Li
Fusheng
F
Agricultural College, Guangxi University, Nanning 530005, China. lifusheng@hotmail.com
Kang
Shaozhong
S
Zhang
Fucang
F
D002245:Carbon Dioxide / Q000494:pharmacology*; D009584:Nitrogen / Q000378:metabolism*; D010788:Photosynthesis; D018526:Plant Transpiration; D014908:Triticum / Q000378:metabolism*; D014867:Water
D014867:Water; D002245:Carbon Dioxide; D009584:Nitrogen