Table 11 Water quality for irrigation according to College of Agricultural Sciences (2002) and U.S. Salinity Laboratory Staff (1954)
EC class | Water quality | EC range (pS/cm) | Usage | SAR class | Water quality | SAR range | Usage |
|---|---|---|---|---|---|---|---|
C1 | Low salinity | 0–250 | Can be used for irrigation of most crops on most soils | S1 | Low sodium | 0–10 | Can be used for all soils |
C2 | Medium salinity | 250–750 | Can be used if a moderate amount of leaching is occurs | S2 | Medium sodium | 10–18 | Preferably used with good permeability |
C3 | High salinity | 750–2250 | Cannot be used with restricted drainage | S3 | High sodium | 18–26 | Can produce harmful effects |
C4 | Very high salinity | > 2250 | Can be used for irrigation of cannot be used with drainage. restricted | S4 | Very high sodium | 26–100 | Unsuitable for irrigation except at low and medium salinity |