Direct Measurements of Evapotranspiration can help steer irrigation forecasts

Direct measurements of Evapotranspiration (ET) in combination with measured or modelled ETp, provide a direct insight into a plant- and location specific water balance and eventual subsequent drought stress that crop has been experiencing. Using further input from measured ETp and/or ETo, completed with the output of numerical weather prediction models for ETp and precipitation quantities (either deterministic- or ensemble prediction system values), a reference crop irrigation forecasts can be generated for the next days. Applying additionally crop specific water needs to the input variables, a crop- and phenological stage- specific forecast for irrigation can be issued for that particular location.