Accurate estimation of crop evapotranspiration (\(ET_{c}\)) considering global warming is a key aspect to optimize water application, yield and fruit quality for sustainable blueberry production. This study quantifies daily crop \(ET_{c}\), diurnal dynamics of the surface energy balance (SEB) and the crop factor (CF) of a drip-irrigated blueberry (Vaccinium corymbosum) orchard field. CF is defined as the ratio of \(ET_{c}\) and reference ET. \(ET_{c}\) and the SEB were measured using an Eddy Covariance (EC) system every 30 min during four growing seasons. Results show maximum values of available energy, Net Radiation (Rn) minus soil heat flux (G), reached 18 MJ m^–2 d^–1, while that the sum of turbulent fluxes extended to 17 MJ m^–2 d^–1. Maximum values of latent heat (\(\lambda E\)) normally occur on November–December from 10 to 11 MJ m^–2 d^–1. The correlation between Rn between crop rows and Rn above the crop canopy-soil surface was 0.73 during all growing seasons. G below the canopy represents 5% of Rn above the crop canopy-soil surface. During this study, \(ET_{c}\) reached up to 5.0 \(mm\, d^{-1}\) when \(ET_{o}\) was 7 \(mm \,d^{-1}\). Maximum \(ET_{c}\) values occur during December. Weekly specific CF varied from 0.5 to 0.8 from October to March. CF showed no significant variation year to year suggesting that they could be used by farmers to better predict water demand and improve water use efficiency. To our knowledge, there are no previous studies at a field’s scale documenting all components of the daily SEB and its diurnal dynamics over blueberry orchards.

考虑到全球变暖，准确估算作物蒸散量 ( \(ET_{c}\) ) 是优化可持续蓝莓生产用水、产量和果实品质的关键方面。本研究量化了滴灌蓝莓 ( Vaccinium corymbosum ) 果园的日作物\(ET_{c}\)、表面能量平衡 ( SEB ) 的昼夜动态和作物因子 ( CF )。CF定义为\(ET_{c}\)与参考 ET 的比率。\(ET_{c}\)和SEB每 30分钟使用涡度协方差 ( EC ) 系统测量一次在四个生长季节。结果显示可用能量的最大值，即净辐射 ( Rn ) 减去土壤热通量 ( G )，达到 18 MJ m ^–2 d ^–1，而湍流通量的总和扩展到 17 MJ m ^–2 d ^–1。潜热 ( \(\lambda E\) )的最大值通常出现在 11 月至 12 月，范围为 10 至 11 MJ m ^–2 d ^–1。在所有生长季节，作物行间的Rn与作物冠层-土壤表面以上的Rn之间的相关性为0.73。树冠下方的G代表Rn的5%高于作物冠层土壤表面。在这项研究中，当\(ET_{o}\)为 7 \(mm \,d^{-1}时， \(ET_{c} \)达到 5.0 \(mm\, d^{-1}\) }\)。最大\(ET_{c}\)值出现在 12 月。从 10 月到 3 月，每周特定CF从 0.5 到 0.8 不等。CF显示每年没有显着变化，这表明农民可以使用它们来更好地预测用水需求并提高用水效率。据我们所知，之前没有在田地规模上记录蓝莓果园日常 SEB 的所有组成部分及其昼夜动态的研究。