- Topic in Gardening courses
Soil pH is a measure for how many H+ ions a soil contains.
pH is defined as the negative logarithm (base 10) of the activity of hydrogen ions (H+) in solution. It ranges from 0 to 14, with 7 being neutral. A pH below 7 is acidic and above 7 is basic.[1] A pH of 6 means that there are 10 times more H+ ions in the soil compared to pH 7, while a pH of 3 means that there are 10,000 times more H+ ions in the soil compared to pH 7.