The relationships between SSA and air-dry moisture content of the soils, and between SSA and cation exchange capacity (CEC), were also investigated.
was used, where y is the SSA measured by pNP, and x is either air-dry moisture content or the CEC, and a and b are coefficients.
These variations are reflected in the wide range of CEC and air-dry moisture content values.
Relation between cation exchange capacity (CEC) and air-dry moisture content of soils with measured and calculated specific surface area (SSA)
1999), for which the SSA (by pNP) and air-dry moisture content were known.
For topsoils, and omitting allophanic samples, the relation between pNP surface area and air-dry moisture content is highly significant (r = 0.
Regression equations relating (i) CEC and (ii) air-dry moisture content to measured and calculated SSAs, are shown in Table 3.
This correlation allows SSA of an independent set of soils to be predicted from their air-dry moisture content with 89% of the variations in SSA being accounted for.
This relation can account for 89% of the variations in SSA of an independent set of soils, suggesting that the air-dry moisture content could be used to estimate the surface areas of topsoils.