Measurement of soil pH

Journal Article · Sat Jan 01 04:00:00 EST 1955 · Soil Sci. Soc. Am., Proc.; (United States)

DOI:https://doi.org/10.2136/sssaj1955.03615995001900020013x· OSTI ID:5654309

Schofield, R K; Taylor, A W

A number of experimental results are presented which show the variation of the pH values of several soils when samples of each are shaken with CaCl/sub 2/ solutions of different concentrations. These results are then interpreted on the basis of the ratio law-derived from the Gouy theory of the electrical double layer - and it is shown that the pH values and electrolyte concentrations show the expected relationship, provided the latter is not too large. The importance of the connection between pH and electrolyte concentration in the routine measurement of soil pH is emphasized, and it is pointed out that such measurements must be carried out using an electrolyte solution of known composition in order to obtain comparable results from different soils. It has been found that 0.01 M CaCl/sub 2/ is the most satisfactory for use in normal non-saline soils where the surface density of electrical charge on the colloidal material is high and independent of the solution composition: This electrolyte concentration is such that measurements made with the usual glass electrode/saturated calomel cell give accurate and reproducible values which are largely independent of the soil/solution ratio, and is yet sufficiently dilute to allow a satisfactory calculation of the lime potential characteristic of the soil sample.

• OSTI ID: 5654309
• Journal Information: Soil Sci. Soc. Am., Proc.; (United States), Journal Name: Soil Sci. Soc. Am., Proc.; (United States) Vol. 19; ISSN SSSAA
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ALKALINE EARTH METAL COMPOUNDS
CALCIUM CHLORIDES
CALCIUM COMPOUNDS
CALCIUM HALIDES
CHEMISTRY
CHLORIDES
CHLORINE COMPOUNDS
ECOLOGICAL CONCENTRATION
ELECTROLYTES
HALIDES
HALOGEN COMPOUNDS
MONITORING
PH VALUE
SOIL CHEMISTRY
SOILS