Converting reactive iron, reactive aluminium, and phosphorus retention index (PRI) to the phosphorus buffering index (PBI) for sandy soils of south-western Australia
M. D. A. Bolland A B C and D. P. Windsor AA Department of Agriculture and Food, PO Box 1231, Bunbury, WA 6231, Australia.
B School of Plant Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.
C Corresponding author. Email: mbolland@agric.wa.gov.au
Australian Journal of Soil Research 45(4) 262-265 https://doi.org/10.1071/SR07026
Submitted: 13 February 2007 Accepted: 21 May 2007 Published: 28 June 2007
Abstract
The recently developed phosphorus (P) buffering index (PBI) is now the national single-point P sorption index to rank the capacity of soil to sorb P. However, before PBI was developed, P sorption was routinely measured by 2 simple procedures in Western Australia: (i) since the mid 1970s, reactive iron (Fe), which is the concentration of Fe extracted from soil by ammonium oxalate; and (ii) since the mid 1980s, the P retention index (PRI), a single-point P sorption index. Both reactive Fe and aluminium (Al) extracted from soil by ammonium oxalalate (reactive Al) have been measured in experiments conducted in Western Australia. Because PBI is now routinely measured in Western Australia there is the need to convert historical reactive Fe, reactive Al, and PRI values to PBI values. In this study we used soil samples collected from 2 field studies and a study of 96 paddocks, all on sandy soil types common in the region, to measure PBI, reactive Fe, reactive Al (not measured in the paddock study), and PRI. We related PBI (dimensionless), as the dependent (y-axis), to reactive Fe (mg/kg), reactive Al (mg/kg), or PRI (mL/g), as the independent (x-axis). The relationships for all data were good for reactive Al (47 data points from the 2 field studies) and PRI (133 data points for the 2 field studies and the paddock study):
However, the relationships was poor for reactive Fe (133 data points) and differed for each of the 2 field studies and the paddock study, so no consistent, reliable approach for converting reactive Fe to PBI values could be determined. We recommend that reactive Fe is no longer used in the region, and that only PBI is used to estimate P sorption.
Acknowledgments
Technical assistance was provided by Mike Baker for the 2 field studies and by John Baker and Leonarda Paszkudzka-Baizert for the paddock study. P sorption was measured by the Chemistry Centre (WA) and CSBP FutureFarm.
Bolland MDA, Allen DG
(2003) Phosphorus sorption by sandy soils from Western Australia: effect of previously sorbed P on P buffer capacity and single-point P sorption indices. Australian Journal of Soil Research 41, 1369–1388.
| Crossref | GoogleScholarGoogle Scholar |
Bolland MDA,
Gilkes RJ,
Brennan RF, Allen DG
(1996) Comparison of seven phosphorus sorption indices. Australian Journal of Soil Research 34, 81–89.
| Crossref | GoogleScholarGoogle Scholar |
Brennan RF,
Bolland MDA,
Jeffery RC, Allen DG
(1994) Phosphorus adsorption by a range of Western Australian soils. Communications in Soil Science and Plant Analysis 25, 2785–2795.
Burkitt LL,
Moody PW,
Gourley CJP, Hannah MC
(2002) A simple phosphorus buffering index for Australian soils. Australian Journal of Soil Research 40, 497–513.
| Crossref | GoogleScholarGoogle Scholar |
Colwell JD
(1963) The estimation of phosphorus fertiliser requirements of wheat in Southern New South Wales by soil analysis. Australian Journal of Experimental Agriculture and Animal Husbandry 3, 190–197.
| Crossref | GoogleScholarGoogle Scholar |
Colwell JD
(1965) An automatic procedure for the determination of phosphorus in sodium hydrogen carbonate extract of soil. Chemistry & Industry 1965, 893–895.
Moody PW
(2007) Interpretation of a single-point P buffering index for adjusting critical levels of the Colwell soil P test. Australian Journal of Soil Research 45, 55–62.
| Crossref | GoogleScholarGoogle Scholar |
Ozanne PG, Shaw TC
(1967) Phosphate sorption by soils as a measure of the phosphate requirements for pasture growth. Australian Journal of Agricultural Research 18, 601–612.
| Crossref | GoogleScholarGoogle Scholar |
Schwertmann U
(1964) Differenzierung der eisenoxide des bodens durch photochemische extraktion mit sauer ammoniumoxalate-losüng. Zeitschrift für Pflanzenernährung und Bodenkunde 105, 194–202.
| Crossref | GoogleScholarGoogle Scholar |
Singh B, Gilkes RJ
(1991) Phosphorus sorption in relation to soil properties for the major soil types of south-western Australia. Australian Journal of Soil Research 29, 603–618.
| Crossref | GoogleScholarGoogle Scholar |