Publication
Title
Effects of sulphate and pH on the plant-availability of phosphate adsorbed on goethite
Author
Abstract
The adsorption of phosphate on metal (hydr)oxides may be influenced by the pH and by the adsorption of other ions. In this study, the influence of sulphate and pH on phosphate adsorption on goethite and the availability to plants of adsorbed phosphate was examined. Maize plants were grown on suspensions of goethite with adsorbed phosphate, containing the same total amount of phosphate and either 0.11 mM or 2.01 mM sulphate at pH 3.7, 4.6 or 5.5. The uptake of phosphorus by the plants increased with the larger sulphate concentration and decreasing pH. Mean P uptake in the treatment with 2.01 mM sulphate and pH 3.7 was 55 mu mol plant(-1), whereas in the treatment with 0.11 mM sulphate and pH 5.5 it was 2 mu mol plant(-1). Batch adsorption experiments using (32)P and speciation modelling of ion adsorption showed that in the presence of sulphate, the phosphate concentration in solution strongly increased with decreasing pH, due to competitive adsorption between sulphate and phosphate on goethite. Modelled phosphate concentrations in solution in the uptake experiment were all below 0.6 mu M and correlated well with the observed P uptake. This correlation indicates that the strong influence of the sulphate concentration and pH on the plant-availability of adsorbed phosphate results from the competition between sulphate and phosphate for adsorption on goethite.
Language
English
Source (journal)
Plant and soil. - 's-Gravenhage
Publication
's-Gravenhage : 1997
ISSN
0032-079X
Volume/pages
197:2(1997), p. 241-249
ISI
000071784700008
Full text (Publisher's DOI)
Full text (publisher's version - intranet only)
UAntwerpen
Publication type
Subject
External links
Web of Science
Record
Identification
Creation 08.10.2018
Last edited 04.07.2021