Table 7 Classification and interpretation of the water quality for irrigation according to the U.S. Salinity Laboratory Staff [100]
Conductivity (EC) | Degree | Range (ppm) | Usage |
|---|---|---|---|
(A) Based on salinity concentrations | Â | Â | Â |
C1 | Low salinity | 100–250 | Used for irrigation with most crops on most soil |
C2 | Medium salinity | 250–750 | Used if moderate leaching occurs |
C3 | High salinity | 750–2250 | It cannot be used with restricted drainage |
C4 | Very high salinity | 2250–5000 | Not suitable for irrigation under ordinary condition |
Sodium percent | Degree | Range (ppm) | Usage |
|---|---|---|---|
(B) Based on Sodium concentrations | Â | Â | Â |
S1 | Low Sodium | 0–10 | Can be used for all soils |
S2 | Medium Sodium | 10–18 | Preferably used with good permeability |
S3 | High Sodium | 18–26 | Good soil management essential |
S4 | Very high Sodium | 26–100 | Unsuitable for irrigation except at low salinity |