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Soil phosphorus forms in hydrologically isolated wetlands and surrounding pasture uplands.
- Source :
-
Journal of environmental quality [J Environ Qual] 2010 Jul-Aug; Vol. 39 (4), pp. 1517-25. - Publication Year :
- 2010
-
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 to 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.
Details
- Language :
- English
- ISSN :
- 0047-2425
- Volume :
- 39
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Journal of environmental quality
- Publication Type :
- Academic Journal
- Accession number :
- 20830938
- Full Text :
- https://doi.org/10.2134/jeq2009.0398