Forms of organic phosphorus in wetland soils

Abstract. Phosphorus (P) cycling in freshwater wetlands is dominated by biological mechanisms, yet there has been no comprehensive examination of the forms of biogenic P (i.e., forms derived from biological activity) in wetland soils. We used solution 31P NMR spectroscopy to identify and quantify P forms in surface soils of 28 palustrine wetlands spanning a range of climatic, hydrogeomorphic, and vegetation types. Total P concentrations ranged between 51 and 3516 μg P g-1, of which an average of 58% was extracted in a single-step NaOH–EDTA procedure. The extracts contained a broad range of P forms, including phosphomonoesters (averaging 24% of the total soil P), phosphodiesters (averaging 10% of total P), phosphonates (up to 4% of total P), and both pyrophosphate and long-chain polyphosphates (together averaging 6% of total P). Soil P composition was found to be dependant upon two key biogeochemical properties: organic matter content and pH. For example, stereoisomers of inositol hexakisphosphate were detected exclusively in acidic soils with high mineral content, while phosphonates were detected in soils from a broad range of vegetation and hydrogeomorphic types but only under acidic conditions. Conversely inorganic polyphosphates occurred in a broad range of wetland soils, and their abundance appears to reflect more broadly that of a "substantial" and presumably active microbial community with a significant relationship between total inorganic polyphosphates and microbial biomass P. We conclude that soil P composition varies markedly among freshwater wetlands but can be predicted by fundamental soil properties.

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Quantitative measures of myo-IP6 in soil using solution 31P NMR spectroscopy and spectral deconvolution fitting including a broad signal

Environmental Science Processes & Impacts ◽

10.1039/c9em00485h ◽

2020 ◽

Vol 22 (4) ◽

pp. 1084-1094 ◽

Cited By ~ 1

Author(s):

Jolanda E. Reusser ◽

René Verel ◽

Emmanuel Frossard ◽

Timothy I. McLaren

Keyword(s):

Nmr Spectroscopy ◽

31P Nmr ◽

Inositol Phosphates ◽

Organic Phosphorus ◽

Terrestrial Ecosystems ◽

31P Nmr Spectroscopy ◽

Inositol Hexakisphosphate ◽

Soil Organic Phosphorus ◽

Broad Signal ◽

Solution 31P Nmr Spectroscopy

Inositol phosphates, particularly myo-inositol hexakisphosphate (myo-IP6), are an important pool of soil organic phosphorus (P) in terrestrial ecosystems.

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Species and environmental geochemistry characteristics of organic phosphorus in sediments of a riverine wetland measured by 31P-NMR spectroscopy

Geochemistry International ◽

10.1134/s0016702915120058 ◽

2015 ◽

Vol 53 (12) ◽

pp. 1141-1149 ◽

Cited By ~ 1

Author(s):

Hezhong Yuan ◽

Wei Pan ◽

Ji Shen ◽

Enfeng Liu ◽

Zhengjie Zhu ◽

...

Keyword(s):

Nmr Spectroscopy ◽

31P Nmr ◽

Organic Phosphorus ◽

Environmental Geochemistry ◽

31P Nmr Spectroscopy ◽

Riverine Wetland ◽

Geochemistry Characteristics

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Speciation and distribution of P associated with Fe and Al oxides in aggregate-sized fraction of an arable soil

Biogeosciences ◽

10.5194/bg-12-6443-2015 ◽

2015 ◽

Vol 12 (21) ◽

pp. 6443-6452 ◽

Cited By ~ 32

Author(s):

X. Jiang ◽

R. Bol ◽

S. Willbold ◽

H. Vereecken ◽

E. Klumpp

Keyword(s):

Nmr Spectroscopy ◽

31P Nmr ◽

Soil Aggregate ◽

31P Nmr Spectroscopy ◽

Alkaline Extraction ◽

Inorganic P ◽

Residual P ◽

Fe Oxides ◽

Total P ◽

Al Oxide

Abstract. To maximize crop productivity fertilizer P is generally applied to arable soils, a significant proportion of which becomes stabilized by mineral components and in part subsequently becomes unavailable to plants. However, little is known about the relative contributions of the different organic and inorganic P bound to Fe/Al oxides in the smaller soil particles. Alkaline (NaOH–Na2EDTA) extraction with solution 31P-nuclear magnetic resonance (31P-NMR) spectroscopy is considered a reliable method for extracting and quantifying organic P and (some) inorganic P. However, any so-called residual P after the alkaline extraction has remained unidentified. Therefore, in the present study, the amorphous (a) and crystalline (c) Fe/Al oxide minerals and related P in soil aggregate-sized fractions (> 20, 2–20, 0.45–2 and < 0.45 μm) were specifically extracted by oxalate (a-Fe/Al oxides) and dithionite–citrate–bicarbonate (DCB, both a- and c-Fe/Al oxides). These soil aggregate-sized fractions with and without the oxalate and DCB pre-treatments were then sequentially extracted by alkaline extraction prior to solution 31P-NMR spectroscopy. This was done to quantify the P associated with a- and c-Fe/Al oxides in both alkaline extraction and the residual P of different soil aggregate-sized fractions. The results showed that overall P contents increased with decreasing size of the soil aggregate-sized fractions. However, the relative distribution and speciation of varying P forms were found to be independent of soil aggregate-size. The majority of alkaline-extractable P was in the a-Fe/Al oxide fraction (42–47 % of total P), most of which was ortho-phosphate (36–41 % of total P). Furthermore, still significant amounts of particularly monoester P were bound to these oxides. Intriguingly, however, Fe/Al oxides were not the main bonding sites for pyrophosphate. Residual P contained similar amounts of total P associated with both a- (11–15 % of total P) and c-Fe oxides (7–13 % of total P) in various aggregate-sized fractions, suggesting that it was likely occluded within the a- and c-Fe oxides in soil. This implies that, with the dissolution of Fe oxides, this P may be released and thus available for plants and microbial communities.

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Determination of neo- and d-chiro-Inositol Hexakisphosphate in Soils by Solution 31P NMR Spectroscopy

Environmental Science & Technology ◽

10.1021/es204446z ◽

2012 ◽

Vol 46 (9) ◽

pp. 4994-5002 ◽

Cited By ~ 92

Author(s):

Benjamin L. Turner ◽

Alexander W. Cheesman ◽

H. Yasmin Godage ◽

Andrew M. Riley ◽

Barry V. L. Potter

Keyword(s):

Nmr Spectroscopy ◽

31P Nmr ◽

31P Nmr Spectroscopy ◽

Inositol Hexakisphosphate ◽

Solution 31P Nmr Spectroscopy

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Mineralisation of soil orthophosphate monoesters under pine seedlings and ryegrass

Soil Research ◽

10.1071/sr03018 ◽

2004 ◽

Vol 42 (2) ◽

pp. 189 ◽

Cited By ~ 35

Author(s):

C. R. Chen ◽

L. M. Condron ◽

B. L. Turner ◽

N. Mahieu ◽

M. R. Davis ◽

...

Keyword(s):

31P Nmr ◽

Inositol Phosphates ◽

Radiata Pine ◽

31P Nmr Spectroscopy ◽

Organic P ◽

Soil P ◽

Predominant Species ◽

Total Soil ◽

Pine Seedlings ◽

Solution 31P Nmr Spectroscopy

The effects of radiata pine (Pinus radiata D. Don) seedlings and ryegrass (Lolium perenne L.) on the mineralisation of orthophosphate monoesters in 7 grassland soils were assessed in a 10-month pot trial using NaOH–EDTA extraction and solution 31P NMR spectroscopy. Extraction with NaOH–EDTA recovered 46–86% of the total soil P, and NaOH–EDTA-extractable organic P determined by molybdate colourimetry ranged between 194 and 715 mg/kg soil, representing 34–85% of the total soil organic P. Orthophosphate monoesters were the predominant species of the extracted organic P in all soils, with much smaller concentrations of orthophosphate diesters, and traces of phosphonates. Concentrations of orthophosphate monoesters were consistently lower in soils under pine (103–480 mg P/kg soil) compared with the initial soils (142–598 mg P/kg soil) and most soils under grass (122–679 mg/kg soil). Mineralisation of myo-inositol hexakisphosphate accounted for 18–100% of the total mineralisation of orthophosphate monoesters in most soils under radiata pine. This suggests that supposedly recalcitrant inositol phosphates are available for uptake by radiata pine, although the extent of this varies among soils.

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