Estimating total crop water use and the associated variability are critical for planning, for the design of supplementary irrigationstrategies and for subsequent management. Tough there have been great advances in estimating actual evapotranspiration,achieving accurate estimates at the field level is still a challenge. The characterization of site specific characteristics influencingevapotranspiration like soil properties impose a great challenge to the use of modeling, and the accurate characterization of thevariability within a field of crop status may bias estimates. Using remote sensing to estimate crop status and energy balance ata fine scale overcome some of these issues. Nevertheless there is a need to have accurate and precise measurements ofevapotranspiration that can serve as validation sites. The eddy covariance method provides the accuracy and footprintnecessary to be used as a reference. Two towers were installed between 2010 and 2015 at two contrasting locations each yearin the south-west of Uruguay at agricultural fields with wheat-soybean crop rotation. The sites were maintained at the samelocation during wheat and soybean. Sites were managed with supplementary irrigation at full demand or without irrigation. Eachtower had instruments to measure in parallel the energy balance (radiometers, flux plates and soil temperature probes), andevapotranspiration directly from eddy covariance (sonic anemometer, IRGA). All locations met fetch requirements, wererepresentative of agricultural fields and were situated in an area dominated by agricultural land. Season long totals showed largevariability depending on crop status and seasonal precipitation regime that determined crop growth and leaf area development.Totals for irrigated fields in the north (Salto, 650-800mm) were higher than in the south (Colonia-Soriano, 600-750), and higherthan standard requirements for the region. This study provides reference values for a significant number of growing conditionsand years for irrigated or rain-fed soybean crops.