The date palm is the main crop in the Southern Arava Valley due to its adaptation to hot, dry conditions and tolerance to saline irrigation water. However, date palms require large water volumes, with common irrigation practices peaking at about 1,000 liters per tree per day in July. With limited local water supply and expanding cultivation, precise irrigation management is critical to control water use and soil salinity.
For over 10 years, irrigation and salinity trials on Medjool date palms have been conducted at the Southern Arava R&D station using large lysimeters. It was found that changes in soil water storage under saline irrigation are minimal, allowing water and solute budgets to be accurately performed without weight-based lysimeters. This enabled the construction of a “giant lysimeter” in 2017, replicating commercial orchard conditions and enabling precise monitoring of irrigation, drainage, and solutes for young to mature trees.
This study aims to develop growth coefficients, fertilization protocols, and calibrate monitoring methods for Medjool date palms in field conditions. Water, solute, and nitrogen balances for eight trees aged six to seven years were measured during 2023–2024. Increases in yield and water use were observed. Daily evapotranspiration (ET) measured by the lysimeter informed growth coefficients for two growing seasons, improving irrigation accuracy while considering salt leaching needs, thus enhancing water and salinity management.
