## 3 Results and Discussion
### Groundwater Quality and Assessment for Irrigation  
The suitability of groundwater irrigation was evaluated based on salinity, alkalinity, the sodium adsorption ratio (SAR), and sodium percentage (%Na) [36,37]. Indeed, high salinity of irrigation water may affect the growth of agricultural plants and soils, which reduces productivity and increases the osmotic pressure of the soil solution [50,51]. The indices of irrigation water quality in the Mornag shallow groundwater samples are given in Table 2. Irrigation water indices calculated in 2013 show that most groundwater samples (1, 2, 3, 4, 5, 9, 11, 12, and 14) are doubtful to unsuitable for irrigation; however, one  
Figure 7: (**a**) Spatial distribution maps of anions for 2013; (**b**) spatial distribution maps of anions for 2016; (**c**) spatial distribution maps of anions for 2019.  
sample (10) indicates doubtful or good water for irrigation, and four samples (6, 7, 8, and 13) indicate good or excellent water class. All groundwater samples in 2016 indicate doubtful to unsuitable water quality, with only one sample (12) having a good water class. Similarly, in 2019, all groundwater samples indicate doubtful to unsuitable water quality, and two water samples (2 and 13) show a permissible to good water class. The soils in the study area are predominantly calcimagnesic soils and rendzines, while in the western and southwest parts of the study area, there is a sandy, silty texture. Under normal irrigation practices, root soils move more water out of the root zone than textured soils. As a result, sandy soils can withstand the higher salinities of irrigation waters. Dissolved salts are leached out of the root zone and may lead to sodification, the degradation of physical soil properties, the dissociation of organic matter, and the salinization of the soil. The examination of the quality indices variation over time shows an irregular pattern over the three years studied. A Wilcox diagram (Figure 8) shows that the Mornag groundwater samples were classified into three-four different categories (permissible, doubtful, good, and excellent). Indeed, the percentage of sodium (% Na) varies significantly with a minimum value in 2013 at P6 and a maximum value at P8 in 2019. For the sodium adsorption ratio (SAR) values, there is an increase that characterizes the P8 well over time, with a minimum calculated in 2013 and a maximum in 2019 (Figure 9). The irrigation water quality index (Table 2) shows that the majority of Mornag groundwater samples have high electrical conductivity and high sodium hazard, suggesting that their quality is generally unsuitable for irrigation (2). \begin{table}
\begin{tabular}{c c c c c c c} \hline  & \multicolumn{2}{c}{**2013**} & \multicolumn{2}{c}{**2016**} & \multicolumn{2}{c}{**2019**} \\ \hline
**Well** & **\%Na** & **SAR** & **\%Na** & **SAR** & **\%Na** & **SAR** \\ \hline
**P1** & 72.4 & 65.9 & 67.8 & 48.7 & 58.2 & 35.9 \\ \hline
**P2** & 56.6 & 42.1 & 66.5 & 39.4 & 50.7 & 17.9 \\ \hline
**P3** & 73.6 & 63.9 & 62.5 & 25.8 & 68.2 & 49.4 \\ \hline
**P4** & 50.3 & 20.2 & 42.8 & 25.8 & 53.1 & 24.2 \\ \hline
**P5** & 60.9 & 25.4 & 44.7 & 27.6 & 69.6 & 81.9 \\ \hline
**P6** & 23.6 & 9.3 & 58.8 & 36.2 & 65.1 & 63.4 \\ \hline
**P7** & 36.2 & 12.0 & 75.2 & 53.5 & 53.4 & 36.7 \\ \hline
**P8** & 29.6 & 8.4 & 59.3 & 37.2 & 70.3 & 114.7 \\ \hline
**P9** & 56.1 & 42.4 & 76.5 & 55.2 & 54.3 & 37.9 \\ \hline
**P10** & 34.3 & 21.7 & 53.5 & 29.0 & 54.8 & 23.2 \\ \hline
**P11** & 49.6 & 22.1 & 72.4 & 119.7 & 50.5 & 19.7 \\ \hline
**P12** & 48.8 & 20.3 & 32.2 & 11.8 & 65.7 & 36.8 \\ \hline
**P13** & 33.7 & 16.1 & 48.8 & 20.2 & 39.8 & 15.4 \\ \hline
**P14** & 66.9 & 40.9 & 62.5 & 53.6 & & \\ \hline \end{tabular}
\end{table} 
Table 2: Irrigation groundwater quality index (2013, 2016, 2019).