Analysis of Water Samples
- pH.
- Total concentration of soluble salts assessed through EC.
- Relative proportion of Na to other Cations such as Ca and Mg, referred to as the Sodium Adsorption Ratio (SAR).
- Concentration of B and other elements that may be toxic to plants.
- Concentration of Carbonates and Bicarbonates as related to the concentration.
- Ca plus Mg, referred to as residual Sodium Carbonate (RSC).
- Content of anions such as chloride and sulphate.
1 | pH | Acidic , Neutral or Basic |
2 | Electrical Conductivity | Ideal value is less than 0.75 mS/cm |
3 | Available S | Precipitation Method |
4 | Calcium | EDTA Titration Method |
5 | Magnesium | EDTA Titration Method |
6 | Sodium adsorption ratio | safe: < 10 And unsafe: > 26 |
7 | Sodium | Flame Photometer Method |
8 | Carbonates and bicarbonates | Simple acidimetric titration |
9 | Chloride | Mohr’s Titration Method |
10 | Residual Sodium Carbonate | safe: < 1.25 And unsafe: > 2.5 |
The limits can vary depending on the type of soil, rainfall and climate conditions. Higher RSC values can be considered safe for sandy soils in a high rainfall area (> 600 mm/year).