CO_2浓度、氮和水分对春小麦光合、蒸散及水分利用效率的影响  

Effects of CO_2 enrichment, nitrogen and water on photosynthesis, evapotranspiration and water use efficiency of spring wheat.

作　　者：李伏生[1] 康绍忠[2] 张富仓[2] 

机构地区：[1]广西大学农学院,南宁530005 [2]西北农林科技大学教育部旱区农业水土工程重点实验室,杨凌712100

出　　处：《应用生态学报》2003年第3期387-393,共7页Chinese Journal of Applied Ecology

基　　金：国家重大基础研究计划项目 (G19990 1170 8);国家杰出青年科学基金资助项目 (4 972 5 10 2 )

摘　　要：研究了不同土壤氮和土壤水分条件下 ,大气CO2 浓度升高对春小麦光合作用、气孔导度、蒸散和水分利用效率的影响 .结果表明 ,CO2 浓度升高 ,干旱处理的春小麦 (TriticumaestivumL .)叶片光合作用速率幅度增加大于湿润处理 ,随着氮肥用量增加光合速率相应增加 ,而不施氮肥增加有限 ;干旱处理气孔导度幅度减少大于湿润处理 ,不施氮肥的大于氮肥充足的 .CO2 浓度升高 ,干旱处理的蒸散量减少比湿润处理多 ,不施氮肥的蒸散量减少较为明显 ;但干旱处理单叶WUE增加大于湿润处理 ;随着氮肥用量增加 ,冠层WUE提高 ,而不施氮肥的冠层WUE最低 .因而CO2 浓度升高、光合速率增加和蒸散量减少会减缓干旱的不利影响 ,增强作物对干旱胁迫的抵御能力 .Spring wheat ( Triticum aestivum L.) was treated with 2 atmospheric CO 2 concentrations (350 and 700 μmol·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 CO 2 increased photosynthetic rate more in drought than in wet treatment. Photosynthetic rate increased with the increase of nitrogen fertilizer. Stomatal conductance decreased with CO 2 enrichment, which was more in drought than in wet treatment. CO 2 enrichment decreased more evapotranspiration in drought than in wet treatment. The decrease was more apparent with no fertilization. CO 2 enrichment increased more leaf water use efficiency in drought than in wet treatment. Canopy WUE increased with CO 2 enrichment and N fertilization. Thus, the increase in photosynthesis and the reduction in evapotranspiration due to elevated CO 2 can ameliorate the negative effects of drought, and increase wheat resistance to water stress.

关 键 词：CO2浓度升高 土壤水分 氮肥用量 蒸散 水分利用效率 

分 类 号：S512.1[农业科学—作物学]