TY  - JOUR
A1  - Hund, Silja V.
A1  - Brown, Sandra
A1  - Lavkulich, Les M.
A1  - Oswald, Sascha Eric
T1  - Relating P Lability in Stream Sediments to Watershed Land Use via an Effective Sequential Extraction Scheme
T2  - Water, air & soil pollution : an international journal of environmental pollution
N2  - High applications of P fertilizers and manure are general practice in intensive agriculture and may cause eutrophication in adjacent streams. Bioavailability of P can be estimated by sequential extractions commonly used for soil or sediment. A single combined method may facilitate more effective comparisons of topsoils and adjoining stream sediments, and enhance management decisions. In this study, the suitability of an established soil P sequential extraction was tested on stream bed sediments. The study was conducted in the Sumas River watershed in the agricultural Lower Fraser Valley, Canada. Sediment samples with differing land use (forest, low and high intensity agriculture) from 1993, 1994, 2008, and 2009 from 14 sites along the Sumas River and tributaries were used. Total sequential extraction concentrations were in agreement with aqua regia digestion (Rs=0.96) and showed consistency over the study time sequence. P fractions released by 0.5 M NaHCO3 (median 14 %), 0.1 M NaOH (33 %), and 1.0 M HCl (38 %) were significantly (alpha=0.05) higher than P released by other extractants. These three extraction steps provide a practical and time-effective assessment of P lability in stream sediments and may be used as a combined scheme for sediment and soil. Analytical results further revealed that land use has a major and characteristic impact on P lability. With a land use change from forest to intensive agriculture, results showed an increase in total P concentrations (30 to 4,000 ppm) and in P lability, in particular for the moderately labile NaOH-P fraction (20 to 50 %).
KW  - Phosphorus
KW  - Eutrophication
KW  - Availability
KW  - Sequential extraction
KW  - Agriculture
KW  - River bed sediment
Y1  - 2013
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/34780
SN  - 0049-6979
SN  - 1573-2932
VL  - 224
IS  - 9
PB  - Springer
CY  - Dordrecht
ER  -