Let's get all scientific for a moment and learn what pH is. In chemistry pH is a measure of how acidic or alkaline a solution is. Okay chemistry lesson over. Basically soil pH is a measure of how acidic or alkaline your soil is. Soil pH is measured on a scale of 1 to 14. If your soil has a pH value of less than 7 then you have acidic soil. On the other hand if your soil has a pH value of greater than 7 then you have alkaline soil. A pH value of 7 is neutral, meaning you have neither acidic or alkaline soil.