Table 2 FAO standard values for chemical ions for clay soil.
From: Design and manufacturing of superabsorbent polymers (SAPs) for agriculture in arid areas
(FAO) Chemical standard for clay soil ions (meq/L) | Range | |
|---|---|---|
Max. | Min. | |
Potassium (K⁺) | 2.0 | 0.1 |
Sodium (Na⁺) | 85.0 | 9.0 |
Calcium (Ca²⁺) | 10.0 | 1.0 |
Magnesium (Mg²⁺) | 2.0 | 0.1 |
Carbonate (CO₃²⁻) | 1.5 | 30.0 |
Bicarbonate (HCO₃⁻) | – | Less than 0.1 |
Chloride (Cl⁻) | 13.0 | 3.0 |
Sulfate (SO₄²⁻) | 6.0 | 1.0 |
