Competitive sorption reactions between phosphorus and organic matter in soil: a review

Title
Competitive sorption reactions between phosphorus and organic matter in soil: a review
Publication Date
2005
Author(s)
Guppy, C
( author )
OrcID: https://orcid.org/0000-0001-7274-607X
Email: cguppy@une.edu.au
UNE Id une-id:cguppy
Menzies, NW
Moody, PW
Blamey, FPC
Type of document
Journal Article
Language
en
Entity Type
Publication
Publisher
CSIRO Publishing
Place of publication
Australia
DOI
10.1071/SR04049
UNE publication id
une:175
Abstract
The incorporation of organic matter (OM) in soils that are able to rapidly sorb applied phosphorus (P) fertiliser reportedly increases P availability to plants. This effect has commonly been ascribed to competition between the decomposition products of OM and P for soil sorption sites resulting in increased soil solution P concentrations. The evidence for competitive inhibition of P sorption by dissolved organic carbon compounds, derived from the breakdown of OM, includes studies on the competition between P and (i) low molecular weight organic acids (LOAs), (ii) humic and fulvic acids, and (iii) OM leachates in soils with a high P sorption capacity. These studies, however, have often used LOAs at 1–100 mm, concentrations much higher than those in soils (generally <0.05 mm). The transience of LOAs in biologically active soils further suggests that neither their concentration nor their persistence would have a practical benefit in increasing P phytoavailability. Higher molecular weight compounds such as humic and fulvic acids also competitively inhibit P sorption; however, little consideration has been given to the potential of these compounds to increase the amount of P sorbed through metal–chelate linkages. We suggest that the magnitude of the inhibition of P sorption by the decomposition products of OM leachate is negligible at rates equivalent to those of OM applied in the field. Incubation of OM in soil has also commonly been reported as reducing P sorption in soil. However, we consider that the reported decreases in P sorption (as measured by P in the soil solution) are not related to competition from the decomposition products of OM breakdown, but are the result of P release from the OM that was not accounted for when calculating the reduction in P sorption.
Link
Citation
Australian Journal of Soil Research, 43(2), p. 189-202
ISSN
0004-9573
1446-568X
1838-6768
1838-675X
Start page
189
End page
202

Files:

NameSizeformatDescriptionLink