Micrometeorological approaches to measure and model surface energy fluxes of irrigated citrus orchards in a semi-arid environment

The object of the research project was to propose and develop innovative theoretical methods for evaluating mass and energy exchange processes within one of the most relevant crop of the agricultural Sicilian context. The study was conceived as a long monitoring program of micrometeorological features of the study orange orchard at different spatial scales (plant, orchard, farm). Different micrometeorological methods, mainly based on Surface Renewal theory, were studied and tested, in order to provide reliable and low cost estimates of sensible heat fluxes within the plant-atmosphere system. Micrometeorological techniques were integrated with in situ measurements of transpiration by up-scaled sap flow techniques, physiological plant features and microclimatic characteristics of the study area. Derived actual crop evapotranspiration fluxes, by means of the resolution of the energy balance equation opportunely corrected for closure, and crop coefficient values were analyzed. All these efforts may contribute to address irrigation water scheduling towards water saving measures.