# Hydrochemical Characteristics and Suitability Assessment of Groundwater Quality for Irrigation
## 3 Results and Discussion
### Hydrochemical Characteristics
The measuring point at Lacarak was uniform in the C3-S1 class except during 2017, when it belonged to the C2-S1 class (Figure 7). Class C2 \"medium salty water\", indicates that it can be used for irrigation with medium intensity leaching. Plants of medium salt tolerance can be grown in most cases without special measures to combat salinity. \"Salty\" water-C3 class, indicates that water cannot be used on poorly drained soils. Even with sufficient drainage, special measures are needed to prevent salinization and the selection of plants with high salt tolerance is also required. Due to the appearance of class C3 in the irrigation season, regular controls and measures must be in line with the assessment of groundwater quality. Authors of classifications such as FAO and USSL indicate the need for different intensity of soil leaching, depending on the type of soil and climatic conditions. This measure includes applying irrigation water in excess of crop requirements for leaching salt from the soil and ensuring the drainage of salt water through well-designed drainage systems [41]. Class S1 indicates that water can be used for irrigation of most soils with little risk of harmful levels of adsorbed Na. However, plants sensitive to Na (some fruits) can accumulate significant amounts, and therefore, this must be monitored. The FAO classification further supported the need for monitoring, with occasional shifts between classes. Results during the observed period are presented in Table 7. At the measuring point at Nikinci, the water quality in terms of salinization did not change from second class, which has moderate limitations for use in irrigation. At the measuring point at Sid, 40% of the results were in first class, and the other samples were in the second class, indicating that moderate measures are necessary when using water for irrigation. The  
Figure 6: Nejgebauer’s classification–percentage representation of classes at all monitoring locations. situation is similar at the measuring point at Lacarak, with the fact that only 10% belonged to the first class and the rest of the measured samples to the second class. In the part of the FAO classification related to water infiltration through the soil profile, at the measuring point at Nikinci, all samples were in first class. At the other two monitoring locations, Sid, and Lacarak, only 10% of the samples belonged to the first class, while the majority of the analyzed samples, 90%, belonged to the second class, indicating moderate restrictions in use. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Nikinci**} & \multicolumn{2}{c}{**Sid**} & \multicolumn{2}{c}{**Lacarak**} \\ \cline{2-5}
**Potential Problems** & \multicolumn{2}{c}{**Class (\%)**} & \multicolumn{2}{c}{**Class (\%)**} & \multicolumn{2}{c}{**Class (\%)**} \\ \hline \multirow{2}{*}{Salinization} & II & 100 & I & 40 & I & 10 \\  & II & 100 & II & 60 & II & 90 \\ \multirow{2}{*}{Infiltration} & I & 100 & I & 90 & I & 90 \\  & I & 100 & II & 10 & II & 10 \\ \multirow{2}{*}{Toxicity of Na\({}^{+}\) Toxicity of Cl\({}^{-}\)} & I & 100 & I & 100 & I & 100 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: The FAO classification-percentage representation of classes. Figure 7: Groundwater quality according to USSL classification on all monitoring locations. In terms of the potential effects of Na\({}^{+}\) and Cl\({}^{-}\), at all monitoring locations, the concentration fell within the first class, indicating no limitations in using water for irrigation in 100% of analyzed samples.