Open AccessEFFECTS OF PHOSPHATE ADDITIONS ON THE CHARGE PROPERTIES OF A PODZOLIC B HORIZON
Author(s) -
M. R. Laverdière
Publication year - 1982
Publication title -
canadian journal of soil science/canadian journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 67
eISSN - 1918-1841
pISSN - 0008-4271
DOI - 10.4141/cjss82-056
Subject(s) - potentiometric titration , adsorption , chemistry , titration , phosphate , ion , inorganic chemistry , electroanalytical method , salt (chemistry) , nuclear chemistry , analytical chemistry (journal) , chromatography , biochemistry , organic chemistry
The Podzolic B horizon of the Calder series sampled in Quebec was incubated at field capacity for 2 yr in the presence of various amounts of P (0–1500 ppm). Total and available P measured after incubation ranged from 179 to 1627 ppm and from 26 to 489 ppm, respectively, following the different P additions. Charge properties were determined using 1 N NH 4 OAc at pH 4.8 and 7.0, potentiometric titration and ion adsorption techniques. The CEC of the sample measured at pH 4.8 varied from 7.2 to 11.4 meq/100 g, while at pH 7.0 it ranged from 9.1 to 16.3 meq/100 g following the 0- to 1500-ppm P additions. This increase in negative charges was attributed to the progressive lowering of the pH zpc (from 4.30 to 3.35 in NaCl) determined by potentiometric titrations of the P-treated samples and as a result of specific P adsorption. Ion adsorption in 0.01 N NaCl showed a gradual increase in Na + adsorbed as a function of pH and amount of P added while an opposite trend was observed for Cl − as a function of pH. P added did not seem to change the amount of Cl − adsorbed or compete for adsorption sites; this would rather demonstrate the specificity of these sites for anion adsorption.