This method determines the pH of soil using a saturated paste prepared from the soil and a pH meter. It is most applicable to soils with a pH ranging from 6.0 to 9.0. Soil pH is the measurement of the relative acidity or alkalinity of the soil solution at equilibrium with the solid particles, it does not indicate the soil’s relative buffering capacity. The method is generally reproducible within ± 0.10 pH units.
U.S. Salinity Laboratory Staff. 1954. pH reading of saturated soil paste. p. 102. In: L. A. Richards (ed.) Diagnosis and improvement of saline and alkali soils. USDA Agricultural Handbook 60. U.S. Government Printing Office, Washington, D.C.
Western Region Method S 1.10, Saturation Paste Soil pH, WCC-103 Publication, WREP-125, 4th Edition, 2013.
