Soil acidity (pH) was analyzed in deionized water and in 0.01 M
CaCl2 using a pH electrode. The electrical conductivity of the suspensions
was measured by using a conductivity electrode. The cation exchange
capacity was determined by using the BaCl2 extraction method
(basic cations) and subsequent measurement with atomic absorption
spectrometry. For the determination of Al, the NaOH titration procedure
was applied. Soil texture was determined using the sedimentation
method according to Moschrefi (1983). Total C and N in soil samples
were determined by dry combustion with an elemental analyzer Carlo
Erba NA 1500 at 1020 °C. Anions in water samples were determined
using ion chromatography.