Effect of aeration on hydrogen-ion concentration of soils in relation to identification of corrosive soils

Abstract

Soils are generally air-dried to obtain comparable results in the measurement of pH. This paper points out the unreliability of such a procedure in measuring the pH of soils for the identification of corrosive areas. Large changes were observed in pH of a poorly drained soil in passing from the moist field condition to the air-dried state and vice versa. This suggested a further investigation, and 62 air-dried soil samples taken from the Natl. Bureau of Standards soil-corrosion test sites were saturated and stored without air for almost 1 yr. Significant changes in pH were observed in the majority of the samples and large changes in many of them. For the identification of areas corrosive to iron and steel, pH measurements of soils should be made on samples maintained in the natural field conditions.