【摘要】 以北京大兴实验站冬小麦为研究对象,依据涡度相关系统和光合测定仪实测数据,分析了冬小麦在叶片和农田尺度上的水分利用率变化特征,并探讨了净光合速率与CO2通量之间的关系.研究发现:冬小麦田间CO2通量与净光合速率在抽穗期最大,拔节期、开花期和灌浆期相差不大;作物水分利用效率的日变化规律在农田尺度和叶片尺度基本相似,即早8∶00～10∶00最大,分别为0.015g/g和0.006g/g,14∶00～18∶00基本稳定,分别为0.006g/g和0.004g/g,20∶00以后水分利用效率接近零.更多还原

【Abstract】 The variation of water use efficiency in leaves and on field scale for winter wheat was analyzed based on data collected by the eddy covariance system and photosynthesis analyzer at Beijing Daxing Experiment Station.The relationship between net photosynthesis and CO2 flux was also discussed.Results showed that winter wheat had the highest net photosynthetic rate and CO2 flux at heading stage,but no differences in those parameters at jointing,flowering and filling periods.The daily water use efficiency on field scale was similar to that in leaves,i.e.the highest at 8∶00~10∶00(0.015 and 0.006 g/g),stable during 14∶00~18∶00(0.006 and 0.004 g/g) and approaching zero after 20∶00.更多还原