“…There are different indirect methods to estimate crop water requirements (Radiation, Blaney-Criddle, PenmaneMonteith equations and Pan Evaporation) based on whether parameters, also direct information from usually one variable of the soilewatereplant system to estimate the soil water content such as the neutron probe and time-domain-reflectometry (TDR), or soil water tension in the soil by tensiometers or gypsum blocks. Nevertheless, all such devices present problems when they are used in large irrigation areas due to temporal and spatial variability of measurements and high costs of installation and management, in addition to sample alteration and low sampling volume (Ojeda-Bustamante, Sifuentes-Ibarra, Slack, & Carrillo, 2004).…”