What is Soil pH ?
It is a measurement of the relative acidity or alkalinity of the soil, providing a guide to the overall chemical balance of the soil.
The pH scale is divided into 14 points:
· A
pH of 7.0 in considered neutral
· A
pH above 7.0 is considered alkaline
· A
pH below 7.0 is considered acidic
Why is pH so important ?
| · | Soil pH is an important factor in plant growth because pH determines the |
availability of soil nutrients to plants. . | |
| · | Plants do not grow well outside the range of 4.5 - 8 |
.
| · | The availability of nutrients differ with the pH level |
| - Calcium and magnesium are much more readily available in alkaline soils | |
| - Iron and manganese are much more readily available in acidic soils | |
| - Most nutrients available in relatively neutral soils (pH 6-7.5) |
| · | Plants preferring certain types of soil are often starved of important nutrients or |
damaged by unwanted minerals. . |
- |
Acid loving plants growing in alkaline soils are often starved of | |
important elements. (eg: iron and manganese) . | ||
- |
Alkaline loving plants growing in acidic soil often cannot access | |
| sufficient calcium and magnesium or are severely damaged by amounts of dissolved aluminium or manganese. |
Potting Mixes & pH
| · | Ideal pH range for potting mixes is between 5.3 and 6.5 although acid loving plants |
prefer a range nearer 4.5 to 5.5 . | |
| · | Potting mix used for a considerable time should have its pH level checked frequently. |
| · | Salts remaining after using ammonium based fertilizers quickly accumulate leaving the |
| mix too acidic for continued optimal growth. |
