**2.1 Study area**

The study area is located in the eastern province of Saudi Arabia and lies about 300 km from Riyadh and 70 km west of the Arabian Gulf (**Figure 1**). The study area consists of Al-Ahsa Oasis, one of the leading agricultural centres in Saudi Arabia and dominated by date palm plantation [29]. The climate in the study area is hot and dry during the summer, with a relatively high air temperature that might exceed 45 °C. However, the winter is wet, with a minimum air temperature that might reach 5 °C. The annual rainfall is less than 250 mm and occurs mainly during the winter [30]. The dominated soils of the study area are sandy to sandy loam soil. Groundwater is the primary water source in the oasis and used mainly for irrigation, domestic and industrial purposes [31]. The land-use system in the study area is predominated by date palm plantation as the main agricultural activity. However, the cropping of rice and vegetables is also practiced in the area.
