Date palm (Phoenix dactylifera L.) is broadly cultivated in hot arid regions of the Middle East and North Africa being one of the most successful and extremely important subsistence crops in these regions (Botes and Zaid, 1999). The kingdom of Saudi Arabia (KSA) is a leading date palm producing country being the third of the top 10 date palm producers (982 546 tones/year) (FAO, 2010). However, there are many regions in KSA which suffer from aridity, salinity and limited water resources (Watanabe et al., 2004; Youssef and Awad, 2008). Moreover, most of agricultural soils in KSA are sandy or sandy loam with high calcium carbonate and poor fertility.