*2.4. Physical-Hydraulic Properties of Substrate*

A tension plate apparatus in a Haines-type assembly [25], with an air-entry value of −180 cm of a water column was employed to define the substrate water retention curve. Substrate sample sized 3 cm in height and 10.2 cm in diameter was positioned on the vibrating porous plate of a Buchner filter funnel to achieve satisfactory packing and following was subjected to gradual wetting from the bottom of the plate until saturation (for 48 h). Measurements of the water content at different pressure heads were taken to obtain the water retention curve. The retention curve was the mean of three substrate samples (n = 3).

Particle size distribution of the substrates was determined with screen analysis. Weighed substrate samples were placed in the top sieve of a column of sieves arranged from top to bottom in descending order of screen mesh size (>20.00, 16.00, 10.00, 8.00, 4.00, 2.00, 1.00, 0.50, 0.25, 0.106 and <0.053 mm) rested on a sieve shaker for 3 min at 30 shakes per minute.

#### *2.5. Statistical Analysis*

The experiment followed a randomized complete block design with two factors that constituted of four lavender species and five NaCl solution irrigation treatments. There were six replications (plants) per species and NaCl solution irrigation treatment. A two-way analysis of variance (ANOVA) was applied to test the significance of the experimental data using SPSS Statistical Software v. 17.0 (SPSS Inc., Chicago, U.S.A.), and treatment means were compared using Tukey HSD test at a probability level *p* < 0.05.

### **3. Results and Discussion**
