This method semi-quantifies the pH of soil using a 1:1 or 1:2 ratio of soil to deionized water and a pH meter. The pH measurements differ from the saturation paste pH by an additional 0.15 – 0.25 pH units for the 1:1 ratio and an additional 0.25 pH units for the 1:2 ratio. Soil pH is 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.
Sample amount requested: 20 g (Sample Amount Guide)
Please contact the Analytical Laboratory with questions concerning limited sample.
References:
Western Region Method S 2.20, Soil pH (1:1) – Soil: DI Water Ration Method, WREP-125, 4th Edition, 2013
Western Region Method S 2.10, Soil pH (1:2) – Soil: DI Water Ratio Method, WCC-103 Publication, WREP-125, 2nd Edition, 2003.
