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| Titel |
Fractionation of organic phosphorus and its distribution in profile soils of Yeyahu Wetland in Beijing, China |
| VerfasserIn |
Min Li, Jin Zhang, Shuang Liu, Qi Cao, Sue White, Michael Whelan |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250057364
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| Zusammenfassung |
| The Yeyahu Wetland Nature Reserve (40Ë 22′04?N to 40Ë 30′31? N; 115Ë 46′16?E to 115Ë
59′48? E) is situated in the northwest of Yanqing County in Beijing, China. The wetland is
the largest in the Beijing area and is dominated by mudflats, reservoir ponds and marshes.
These components are linked together by the Guishui River. The wetland receives
contaminated water from domestic sewage and garbage, limited industrial pollution,
agricultural nonpoint pollution and sediment from soil erosion. Making long-term
improvements in water quality in the wetland depends on the reduction of P inputs from the
atmosphere, influent rivers and runoff.
Organic phosphorus (OP) plays an important role in soil biogeochemical cycles and is a
potential source of P for the productivity of the wetland. Different OP fractions must be
extracted from soils before analysis, which is subject to the chemical solubility of fractions in
extractants. The aim of this study was to investigate the OP form, composition and
bioavailability in soils within the Yeyahu Wetland using an appropriate method of OP
fractionation. A sequential extraction scheme was modified from Bowman and Cole (1978),
Ivanoff et al. (1998) and Fisher (2007) in order to increase extraction efficiency by changing
shaking time, pH in the acidifying procedure (pH moderately labile OP > moderately resistant
OP > labile OP. These fractions accounted for 2.1-41.1%, 8.4-14.1%, 0.9-8.4% and
0.25-2.8% of TP, respectively. Different OP fractions were all positively correlated with TP,
moisture content and organic matter. It can be seen that organic matter contributed
significantly to the content of different OP fractions in soils. The negative but significant
correlation between pH and OP fractions indicates that pH was one of the important
factors to the content of OP fractions in soils. Moderately labile OP accounting for
a larger ratio of total OP and it was positively correlated with soil clay and silt
contents. Meanwhile, it showed an apparently negative correlation with soil sand
contents.
As a result, attention should be paid to OP as a potential portion of the bioavailable P in
soils, particularly in the native alkaline and neutral soils of Yeyahu Wetland. Future studies
should evaluate the structural composition of OP fractions using effective 31P NMR
spectroscopy in order to support the conclusions derived from sequential extraction
procedures. |
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