Evapotranspiration is the largest outgoing water flux from the Earth's surface
its accurate quantification is critical for the crop development in conditions of the climate changes from recent decades, and it can contribute to a greater understanding of a range of agricultural ecosystem processes. To evaluate the hydric requirements of the crops, it was agreed that they should be reported to a maximum global evapotranspiration called potential evapotranspiration. To estimate this variable, a variety of methods were developed, each with its benefits as well as trade-offs. Their use, however, is laborious due to their complexity and of the large number of parameters required. In this book, specialists' concerns worldwide to develop simple but reliable methodologies - with less data requirement - which will give accurate and appropriate results - are presented. In addition, a study of the physics of the moisture evaporation process from porous media to elucidate what are the mechanisms of moisture migration from granular biopesticides is presented in the last chapter.