Fluctuating water table effect on phosphorus release and availability from a Florida Spodosol

  • Augustine K. Obour
  • Maria L. Silveira
  • Joao M. B. Vendramini
  • Lynn E. Sollenberger
  • George A. O’Connor
Original Article

DOI: 10.1007/s10705-011-9456-y

Cite this article as:
Obour, A.K., Silveira, M.L., Vendramini, J.M.B. et al. Nutr Cycl Agroecosyst (2011) 91: 207. doi:10.1007/s10705-011-9456-y

Abstract

Spodosols in Florida exhibit a unique hydrology including a fluctuating water table that can often reach the surface horizon during the summer months. This paper evaluated the effects of fluctuating water table on P fluxes and availability in a typical Florida Spodosol. The study was conducted on an established bahiagrass (Paspalum notatum Flügge) pasture grown on a Smyrna sand (sandy, siliceous, hyperthermic Aeric Alaquods). Phosphorus fluxes were measured using suction cup lysimeters installed at depths of 15, 30, 60, 90, and 150 cm. The 15- and 30-cm deep lysimeters were located above the spodic (Bh) horizon, whereas the remaining lysimeters (60-, 90- and 150-cm) were below the Bh horizon. A pressure transducer was installed at the center of the experimental site to monitor changes in water table depth. Two anion exchange membranes (2 × 6 cm) were buried in each plot at a 15-cm depth to estimate in situ P availability. During the 2-year study, leachate P concentrations in the lysimeters above the Bh horizon increased as water tables rose in the months of August and September. Conversely, P concentration measured in the lysimeters below the Bh horizon remained relatively constant (0.02 mg L−1). Soil P availability also increased (from 3.2 μg cm−2 in June to 9.2 μg cm−2 in August) in response to rising water table. Results showed that the fluctuating water table conditions experienced during the summer months in Florida cause upward flux of P from the Bh horizon, which increased soil P availability and susceptibility to off-site transport.

Keywords

Anion exchange membranesPhosphorus availabilitySpodosolWater table

Abbreviations

AEM

Anion exchange membranes

EPCO

Equilibrium P concentration

M1-P, M1-Al, M1-Fe, respectively

Mehlich 1 P, Al, and Fe concentrations

PSR

Phosphorus saturation ratio

SPSC

Soil P storage capacity

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  • Augustine K. Obour
    • 1
  • Maria L. Silveira
    • 1
  • Joao M. B. Vendramini
    • 1
  • Lynn E. Sollenberger
    • 2
  • George A. O’Connor
    • 3
  1. 1.Range Cattle Research and Education CenterUniversity of FloridaOnaUSA
  2. 2.Agronomy DepartmentUniversity of FloridaGainesvilleUSA
  3. 3.Soil and Water Science DepartmentUniversity of FloridaGainesvilleUSA