TY  - JOUR
AU  - Jiang, Xiaoqian
AU  - Klumpp, Erwin
AU  - Cade-Menun, B. J.
AU  - Bol, Roland
AU  - Nischwitz, Volker
AU  - Willbold, Sabine
AU  - Vereecken, Harry
AU  - Bauke, S. L.
AU  - Amelung, Wulf
TI  - Colloid-bound and dissolved phosphorus species in topsoil water extracts along a grassland transect from Cambisol to Stagnosol
JO  - Biogeosciences
VL  - 14
SN  - 1726-4170
CY  - Katlenburg-Lindau [u.a.]
PB  - Copernicus
M1  - FZJ-2017-02115
SP  - 1153-1164
PY  - 2017
AB  - Phosphorus (P) species in colloidal and "dissolved" soil fractions may have different distributions. To understand which P species are potentially involved, we obtained water extracts from the surface soils of a gradient from Cambisol, Stagnic Cambisol to Stagnosol from temperate grassland in Germany. These were filtered to  <  450 nm, and divided into three procedurally defined fractions: small-sized colloids (20–450 nm), nano-sized colloids (1–20 nm), and "dissolved P" (<  1 nm), using asymmetric flow field-flow fractionation (AF4), as well as filtration for solution 31P-nuclear magnetic resonance (NMR) spectroscopy. The total P of soil water extracts increased in the order Cambisol  <  Stagnic Cambisol  <  Stagnosol due to increasing contributions from the dissolved P fraction. Associations of C–Fe/Al–PO43−/pyrophosphate were absent in nano-sized (1–20 nm) colloids from the Cambisol but not in the Stagnosol. The 31P-NMR results indicated that this was accompanied by elevated portions of organic P in the order Cambisol  >  Stagnic Cambisol  >  Stagnosol. Across all soil types, elevated proportions of inositol hexakisphosphate (IHP) species (e.g., myo-, scyllo- and D-chiro-IHP) were associated with soil mineral particles (i.e., bulk soil and small-sized soil colloids), whereas other orthophosphate monoesters and phosphonates were found in the "dissolved" P fraction. We conclude that P species composition varies among colloidal and "dissolved" soil fractions after characterization using advanced techniques, i.e., AF4 and NMR. Furthermore, stagnic properties affect P speciation and availability by potentially releasing dissolved inorganic and ester-bound P forms as well as nano-sized organic matter–Fe/Al–P colloids.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000396169300003
DO  - DOI:10.5194/bg-14-1153-2017
UR  - https://juser.fz-juelich.de/record/828118
ER  -