Crop evapotranspiration: An approach to main methods applied to scientific researches and in agriculture

Abstract

There are many methodologies for measuring or estimating crop evapotranspiration (ETc). These methodologies differ greatly from each other depending on the approach (empirical, physical or a combination of both), technological level, input dataset, application area, cost and accuracy. This wide diversity is related to the complexity involved in water transference from the soil-plant system to the atmosphere, within various climatic conditions around the Earth and also to the different types of vegetation. In this review, the following methods were described and reviewed: lysimeter (LIS), soil water balance (BAS), Bowen ratio-energy balance (RBBE), eddy covariance (CVT), sap-flow models (MFS), chamber system (SC) and, crop coefficient-based methods (MBKc). Finally, the methods based on surface energy balance (SRBE) and vegetation indices (SRIV) were estimated through remote sensing data (SR).These methods were selected because they are considered, within their type of approach (hydrological, micrometeorological, physiological, empirical and remote sensing), the most widespread among the international scientific community and in agriculture.