中文摘要：

采用涡度相关技术监测夏玉米各生育期农田系统的CO2通量和潜热通量，得到夏玉米各生育期农田CO2通量、潜热通量以及农田水分利用率的日变化特征。结果表明，夏玉米各生育期农田系统CO2通量日变化趋势基本相同，都呈单谷型分布；潜热通量的日变化曲线呈先升高后降低的分布状态，且潜热通量最高值以抽穗期最高；灌浆期农田水分利用率大于其他生育期。

英文摘要：

The latent heat flux and flux under different stages of field ecosystem were measured by eddycorrelation technique, and the daily characteristics of the flux, latent heat flux and water use efficiency offield system for all the growth stages were analyzed. The results indicated that the daily changes of fluxunder different stages had the same trend with single valley, and the daily latent heat flux changed with unimodal curve, and the peak of latent heat flux in maize heading stage was higher than that in the otherstages. The water use efficiency of field system in filling stage was higher than those in the other stages.