Interpretation of Results of Irrigation Water Analysis and Recommendations
Interpretation of Results of Irrigation Water Analysis and Recommendations
The Quality of Irrigation Water has been Determined by the Following Chemical Characteristics.
1. Total concentration of soluble salts or salinity (EC).
2. Concentration of sodium ions in proportion to calcium plus magnesium or sodicity ( SAR).
3. Concentration of carbonates and bicarbonates ions in excess of calcium plus magnesium. (PSC)
4. Trace elements viz, 3 etc.
1. Salinity classes of Irrigation Water:
Sr.No | Conductivity dSm-1 | Class | Interpretation |
1 | Less than 0.25 | C1 | Excellent |
2 | 0.25 to 0.75 | C2 | Good |
3 | 0.75-2.25 | C3 | Doubtful |
4 | Above 2.25 | C4 | Unsuitable |
2. Sodium (Alkali Hazards (SAR) :
SAR | Class | Interpretation |
1-10 | S1 (Low) | Can be used for irrigating almost all soils. |
10-18 | S2 ( Medium) | Appreciable sodium hazard with fine textured soils having high CEC and under low leaching conditions. Can be safely use on coarse textured soils having good permeability. |
18-26 | S3( High) | May produce harmful level of sodium in most soil and will require special soil management good drainage, high leaching and high levels of organic matter. |
Above 26 | S4 ( Very High ) | Generally unsatisfactory for irrigation. |
Salt content (g/L) – 0.640 X EC (dSm-1)
Salt Content (g/L) | Evaluation |
0.2 to 0.5 | Water of best quality |
1.0 to 2.0 | Water with possibility to create salinity. |
3.0 to 7.0 | Water to be used with leaching and perfect drainage |