Evapotranspiration over an irrigated orange orchard using micrometeorological techniques and sap flow measurements

During recent years, a substantial progress in understanding the evolution of evapotranspiration processes in cropping systems has produced detailed models and innovative measurement techniques for describing the mass (water, CO2) and energy (solar radiation) exchanges in the soil-plant-atmosphere continuum. Within this context, the aim of the study was to investigate, develop and validate integrated approaches to better understand and quantify mass and energy exchange processes in an orange orchard in the Mediterranean environment. Different micrometeorological techniques (i.e. surface renewal analysis of sensible heat flux, surface energy balance) were used to estimate the evapotranspiration fluxes of the irrigated orange grove in eastern Sicily (Italy). Transpiration was determined by the sap flow method. The results showed satisfactory comparisons between the investigated methods. The findings of this study will allow for the definition of suitable techniques and methodology for the rational management of water resources in the tree crop environment under water scarcity conditions.