Preface

This second volume presents an overview of the direct measurement techniques of evapotranspiration with related applications to the water use optimization in the agricultural practice and to the ecosystems study. The measurements are necessary to evaluate the spatial and temporal variability of ET and to refine the modeling tools. Besides the basic concepts, examples of applications of the different measuring techniques at leaf level (porometry), at plant-level (sap-flow, lysimetry) and agro-ecosystem level (Surface Renewal, Eddy Covariance, Multi layer BREB) are illustrated in detail. The agricultural practice requires a careful management of water resources, especially in the areas where water is naturally scarce. The detailed knowledge of the transpiration demands of crops and different cultivars, as well as the testing of new irrigation techniques and schemes, allows the optimization of the water consumptions. Besides some basic concepts, the results of different experimental irrigation techniques in semi-arid areas (e.g. subsurface drip) and optimization of irrigation schemes for different crops in open-field, greenhouse and potted grown plants are presented. Aspects on ET from crops in saline environments are also presented. Finally, effects of ET on groundwater quality in xeric environments as well as the application of ET to climatic classification are presented. All the works, chosen from well reputed researcher in the field, have been carefully peer reviewed and contribute to report the state of the art of the ET research in the different applicative fields. The book provides an excellent overview both for the researchers and the students who intends to address these issues