『(Abstract)
Newly created and restored wetlands play an important role in
sequestering excess nutrients at the landscape scale. In evaluating
the long-term efficacy of nutrient management strategies in increase
wetland capacity for sequestering P, information is needed on
the forms of P found across the upland-wetland transition. To
assess this, we studied soils (0-10 cm) from four wetlands within
cow-calf pastures north of Lake Okeechobee, FL. Wetlands contained
significantly (P＜0.05) greater concentrations of organic matter
(219 g C kg-1), total P (371 mg P kg-1),
and metals (Al, Fe) relative to surrounding pasture. When calculated
on an aerial basis, wetland surface soils contained significantly
greater amounts of total P (236 kg ha-1) compared with
upland soils (114 kg ha-1), which was linked to the
concomitant increase in organic matter with increasing hydroperiod.
The concentration of P forms, determined by extraction with anion
exchange membranes, 1 mol L-1 HCl, and an alkaline
extract (0.25 mol L-1 NaOH and 50 mmol L-1
ethylenediaminetetraacetic acid [EDTA]) showed significant differences
between uplands and wetlands but did not alter as a proportion
of total P. Speciation of NaOH-EDTA extracts by solution 31P
nuclear magnetic resonance spectroscopy revealed that organic
P was dominated by phosphomonoesters in both wetland and pasture
soils but that myo-inositol hexakisphosphate was not detected
in any sample. The tight coupling of total C and P in the sandy
soils of the region suggests that the successful management of
historically isolated wetlands for P sequestration depends on
the long-term accumulation and stabilization of soil organic matter.』
Abbreviations
(Introduction)
Materials and methods
Site description
Soil sampling
Hydroperiod determination
Soil physical and chemical properties
Phosphorus characterization
Solution 31P NMR spectroscopy
Data analysis
Results and discussion
Soil physicochemical characteristics
Soil phosphorus pools
Solution 31P NMR spectroscopy
Impact of hydroperiod
Phosphorus storage
Conclusions
Acknowledgments
References
※リンの抽出には、Reddy et al.（1998）などを使用。