Mixing
Fertilisers differ in the amounts that can be dissolved in water. Most fertilisers dissolve more readily in warm or hot water.
When making up concentrated stock solutions it is helpful to know the solubility of the chemicals involved. Some examples are listed in Table 1 below.
Fertiliser | Solubility in water @ 20ºC (g/L) |
---|---|
Ammonium nitrate | 1902 |
Ammonium sulphate | 750 |
Boric acid | 49 |
Calcium nitrate | 1290 |
Magnesium sulphate | 330 |
Potassium chloride | 340 |
Potassium nitrate | 316 |
Potassium sulphate | 111 |
Urea | 1000 |
Remember, if a stock solution is heated to dissolve the components, the fertiliser may crystallise when the solution cools down. To avoid this, dilute the solution or use it immediately.