Soil pH is the degree to which soil is acidic or alkaline. It is a measure of hydrogen ions in the soil. The more hydrogen ions in the soil, the more acidic the soil becomes. The less hydrogen ions, the more alkaline.
PH is a logarithmic measure and I’m sure I’m not the only one who feels the shudder down the spine hearing the word logarithm…. I’m not even going to try to define it because I’m not a mathematician…. However, for our gardening purposes, pH is measured from 0 to 14.
Basically, zero is extremely acidic, 7 is neutral and 14 is extremely alkaline. Likewise, soil with a pH of 6 is 10 more times acidic than a soil with a pH of 7. A soil with a pH of 5 is 10 times more acidic than a soil with a pH of 6.
When we think about chlorinated swimming pools we realise that the best pH of a swimming pool is 7.4. That’s because the eyes, blood and other parts of the human body should have a pH of 7.4. I say ‘should have’ because obviously anyone with an extremely acidic diet would have a pH of less than the optimum 7.4 and is likely to have health issues associated with an acidic diet.
If the pH of the swimming pool were say 6.5 it would be almost 10 times too acidic and start to burn our eyes or perhaps dissolve our skin and other parts of the body and any metal piercings the swimmer was wearing. So if we look at soil in the same way as our swimming pool we can appreciate that soils have a pH. Some soil is more acidic than others and some soil has more life, biological activity is healthier than other soils.
Find out if your soil is hydrophobic by clicking here.