Revisiting the Feddes reduction function for modeling root water uptake and crop transpiration

The widely used Feddes reduction function (FRF) was reviewed in the context of its merits and shortcomings for modeling root water uptake (RWU), crop transpiration, and soil water balance components. The empirical nature of the FRF was contrasted to few calibrations reported in the literature, and the conditions where the correct operation of the FRF was of limited importance were discussed. Some alerts regarding the feasibility of this function...