Abstract
Soil pH is related to the hydrogen ion (H+) activity of the soil-water system. The chemical definition of pH is as follows: pH=-log (H+). In other words, for a pH drop of 1 unit (e. g. from pH 6 to pH 5) there will be a ten~fold increase in H+ activity in the soil solution. If pH 1 rises by 1 unit, only one-tenth as much acidity will be present in solution. As such, pH is only a measure of the active acidity in the soil water solution bathing plant roots. This fraction of total soil acidity is extremely small. It would take less than 1/2 pound of calcitic lime per acre to neutralize the active acidity contained in the soil solution of 8 inches of pH 5.0 silt loam topsoil at field moisture capacity.
Publication Date
10-1982
Volume
3
Number
9
Repository Citation
Grove, John H., "Soil pH: What It Is, How It Is Measured, Why It Is Important" (1982). Soil Science News and Views. 160.
https://uknowledge.uky.edu/pss_views/160
