A drip irrigation system was installed, with two lines per tree
row and 9.33 pressure-compensated emitters (1.6 L h−1) per tree
placed every 75 cm. Irrigation was scheduled weekly with a frequency
that varied from 1 to 2 times per day in spring–summer
to 2–5 irrigations per week for the rest of the year. Trees were
irrigated at 120% of crop evapotranspiration (ETc) to maintain nonlimiting
soil water conditions. ETc was determined as the product
of reference crop evapotranspiration (ET0) and the crop coefficients
(between 0.25 and 0.55) proposed by the Agricultural Information
System of Murcia (www.siam.es) for this area, adjusted for the tree
size (Fereres and Goldhamer, 1990), and an additional leaching
fraction applied due to the irrigation water salinity