Please use this identifier to cite or link to this item:
https://hdl.handle.net/1959.11/19704
Title: | Spectral sensitivity of solution ³¹P NMR spectroscopy is improved by narrowing the soil to solution ratio to 1:4 for pasture soils of low organic P content | Contributor(s): | McLaren, Timothy (author); Smernik, Ronald J (author); Simpson, Richard J (author); McLaughlin, Michael J (author); McBeath, Therese M (author); Guppy, Christopher (author) ; Richardson, Alan E (author) | Publication Date: | 2015 | DOI: | 10.1016/j.geoderma.2015.02.004 | Handle Link: | https://hdl.handle.net/1959.11/19704 | Abstract: | Solution phosphorus (P) nuclear magnetic resonance (NMR) spectroscopy following extraction with sodium hydroxide-ethylenediaminetetraacetic acid (NaOH-EDTA) is the most powerful and widely used technique for characterising soil organic P. However, poor spectral sensitivity (related to the signal to noise ratio) can limit its applicability for soils of low organic P content, especially in subsurface layers. Sensitivity can potentially be improved by employing a much narrower (1:4) soil to solution ratio than usual (1:10 or 1:20), which increases the density of P in the NMR tube. Pasture soils were collected at two depths (0-4cm and 4-10cm) from across the high rainfall zone of eastern Australia, and were extracted with NaOH-EDTA at a 1:4 and 1:10 extraction ratio. The extracts were analysed for molybdate-reactive P (i.e. an estimate of inorganic P), and total extractable concentrations of aluminium (Al), iron (Fe), magnesium (Mg), manganese (Mn) and P using inductively coupled plasma optical emission spectroscopy (ICP-OES). Total concentrations of P in soil were determined by laboratory X-ray fluorescence. Extraction efficiency of total soil P was on average only slightly lower for the 1:4 extracts (41%) than for the 1:10 extracts (47%). Extraction efficiencies for paramagnetic (Fe, Mn) and non-paramagnetic (Al, Mg) metals were also similar at the two extraction ratios. Solution ³¹P NMR spectra of 1:4 extracts were considerably better in terms of spectral sensitivity than those of the 1:10 extracts, particularly for soils of low organic P content. This study demonstrates that in soils of low organic P content, NaOH-EDTA extraction using a 1:4 soil to solution ratio is a viable alternative to the more commonly used 1:10 soil to solution ratio. | Publication Type: | Journal Article | Source of Publication: | Geoderma, v.257-258, p. 48-57 | Publisher: | Elsevier BV | Place of Publication: | Netherlands | ISSN: | 1872-6259 0016-7061 |
Fields of Research (FoR) 2008: | 050304 Soil Chemistry (excl. Carbon Sequestration Science) | Fields of Research (FoR) 2020: | 410604 Soil chemistry and soil carbon sequestration (excl. carbon sequestration science) | Socio-Economic Objective (SEO) 2008: | 961402 Farmland, Arable Cropland and Permanent Cropland Soils | Socio-Economic Objective (SEO) 2020: | 180605 Soils | Peer Reviewed: | Yes | HERDC Category Description: | C1 Refereed Article in a Scholarly Journal |
---|---|
Appears in Collections: | Journal Article |
Files in This Item:
File | Description | Size | Format |
---|
SCOPUSTM
Citations
17
checked on Mar 23, 2024
Page view(s)
1,150
checked on Apr 21, 2024
Items in Research UNE are protected by copyright, with all rights reserved, unless otherwise indicated.