Implementing a new texture-based soil evaporation reduction coefficient in the FAO dual crop coefficient method

Crop evapotranspiration (ET) is a fundamental component of the hydrological cycle, especially in arid/semi-arid regions. The FAO-56 offers an operational method for deriving ET from reduction (dual crop coefficient Kc) atmospheric evaporative demand (ET0). dual approach (FAO-2Kc) intended to improve daily estimation by separating contribution bare soil evaporation (E) and transpiration components. FAO-2Kc has been well-known reference monitoring water needs. However, its performance estimating use efficiency limited uncertainties modeled evaporation/transpiration partitioning. This paper aims at improving module modifying E (Kr) according texture information state-of-the-art formulations, hence, amend mismatch between field-measured data beyond standard conditions. In practice this work evaluates two models, using classical Kr (Kr,FAO) new texture-based (Kr,text) over 33 sites under different An offline validation investigated forcing both models with observed moisture (?s) as input. Kr,text methodology provides more accurate estimations compared Kr,FAO systematically reduces biases. Using allows reaching lowest root means square error (RMSE) 0.16 mm/day where RMSE reached 0.88 mm/day. As step further assessment proposed methodology, was estimated three wheat fields across entire agricultural season. Both approaches were thus inter-compared terms estimates forced SM residual balance model (online validation). Compared measurements, formulation provided results. 0.66 (0.71 mm/day) R2 0.83 (0.78) (classical) Kr.