D4972-95a Standard Test Method for pH of Soils Copyright 1997
AMERICAN SOCIETY FOR TESTING AND MATERIALS, West Conshohocken,
PA. All rights reserved. 1.1 This test method covers the
measurement of the pH of soils for uses other than for corrosion
testing. Such measurements are used in the agricultural,
environmental, and natural resources fields. This measurement
determines the degree of acidity or alkalinity in soil materials
suspended in water and a 0.01 calcium chloride solution.
Measurements in both liquids are necessary to fully define the
soil's pH. This variable is useful in determining the solubility
of soil minerals and the mobility of ions in the soil and
assessing the viability of the soil-plant environment. A more
detailed discussion of the usefulness of this parameter is not
warranted here; however, it can be found in many discussions of
the subject. A few such discussions are given as Refs (1)
through (6) at the end of the text. 1.2 The values given in SI
units are to be regarded as the standard