Tells you if your soil is acid or akaline

I think it's all to do with the concentration of hydrogen ions...the pH scale is from 1 - 14, 7 is neutral..below 7 is acidic and above 7 is alkaline :0/

The pH of the soil has a lot to do with how soluble various nutrients are in the soil, and so how available they are to the plants. Alkaline soils--with a high pH--tend to keep micronutrients and phosphate bound up in insoluble compounds that many plants can't use. Plants that are adapted to low pH soils--acid lovers--develop chlorosis in alkaline soils, because they cant get enough iron, manganese, zinc, etc. Plants that withstand alkaline soils are usually better off in a slightly acid soil, but strongly acid soils stop the growth of the bacteria that break organic nitrogen compounds into forms that plants can use, so normal to lime-loving plants often suffer from nitrogen deficiency in peaty soils.

thanks for all the information on pH but i still do not know what the initials pH stand for. Fred.

Sorry, Fred! From Wikipedia:

"In chemistry, pH (short for potentiometric hydrogen ion concentration) is a measure of the acidity or basicity of a solution. It approximates but is not equal to
p[H], the negative logarithm (base 10) of the molar concentration of dissolved hydrogen ions (H+)."

Hope that's a little more to the point than my previous blather. : )