Standard Test Methods for pH of Soils

Importancia y uso:

5.1 The pH of the soil is a useful variable in determining the solubility of soil minerals, the mobility of ions in the soil, and assessing the viability of the soil-plant environment.

5.2 pH measurements are made in both test water and a calcium chloride solution because the calcium displaces some of the exchangeable aluminum. The low ionic strength counters the dilution effect on the exchange equilibrium by setting the salt concentration of the solution closer to that expected in the soil solution. The pH values obtained in the solution of calcium chloride are slightly lower than those measured in water due to the release of more aluminum ions which then hydrolyses. Therefore, both measurements are needed to fully define the character of the soil's pH.

5.3 For the purpose of these test methods, the test specimens are sieved through a 2.00 mm (No. 10) sieve. Measurements on soils or soil fractions having particle sizes larger than 2.0 mm by these test methods may be invalid. If soil or soil fractions with particles larger than 2.0 mm are used, it must be stated in the report since the results may be significantly different.

Note 2: The quality of the result produced by this standard is dependent on the competence of the personnel performing it and the suitability of the equipment and facility used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some, but not all, of those factors.

Subcomité:

D18.22

Referida por:

D8151-19E01, D5988-18, D5268-23, F2747-19, D2976-22A, E2278-13R19, E2060-22, D7294-13R21, F3339-20, D8262-22, E2277-14R19, F2396-11R19, D7100-11R20, E2243-13R19

Volúmen:

04.08

Número ICS:

13.080.10 (Chemical characteristics of soil)

Palabras clave:

acidity; alkalinity; pH; reaction; soil;