Rising temperatures and dwindling groundwater resources demand significant improvements of water productivity in irrigated agriculture especially in arid regions. In arid regions the prevailing drought conditions are getting harsher. Groundwater resources are mostly nonrenewable and surface water resources are often absent due to low average annual rainfall and high evaporation. On the other hand, the quality of the available water is decreasing rapidly (Ragab and Prudhomme, 2002). The Gulf Cooperation Council (GCC) countries are experiencing these water shortage problems, which threatens the agricultural development (Saif et al, 2014; El-Rashed & Sherif, 2000).
Date palm is a major crop of arid regions, but up to now, only a very small number of investigations systematically explored the relation of yield and water supply for these crops (Car et al, 2012; Sperling et al, 2012; Liebenberg and Zaid, 2002). Also, a more detailed water balance for the root zones from date palms in arid countries is currently not available.
A UPAR grant project 31F057 was conducted in the UAE and demonstrated that commonly used water requirement figures of date palms exaggerate their real water consumption by 20 to 50% and that irrigation schedules of date palms should be based on water stress measurements in the root zone of date palms (Lennartz and Kloss, 2016).
To fully understand the interaction between the irrigation practices and the water balance of the root zone from a date palm a comprehensive soil water model for these crops needs to be set up. Therefor, the aim of this study is to analyze and quantify the dynamic (soil)water processes in the root zone of the date palms during irrigation.
The UPAR grant project 31F057 research provides the data needed to further improve and set up the HYDRUS 2D/3D model, such as soil and climate parameters, soil water variables, irrigation and sap flow data. First, a simple draft water balance of the root zone using a simple bucket approach was made. Then quantifying the deep drainage during irrigation and the water abstraction by the palm. Finally, a detailed soil water model is set up using HYDRUS 2D/3D to indicate the soil water processes during irrigation.