Tuesday, November 6, 2007 - 2:30 PM
207-5

Evaluating Phosphorus Availability in Vermont Floodplain Soils.

Caroline Alves1, Eric Young2, and Donald Ross2. (1) USDA-NRCS, USDA/NRCS, 1193 S Brownell Rd. Ste 35, Williston, VT 05461, (2) Plant and Soil Science, University of Vermont, 105 Carrigan Drive, Burlington, VT 05405

Landscape variability and phosphorus (P) concentrations in floodplain and stream bank area soils can affect the fate and transport of P. We are currently characterizing P availability in some floodplain soils of major extent along two stream corridors in Vermont. The objective is to determine if P levels vary significantly with depth and among soil series. Samples were taken every 15 cm to a depth of 105 cm from ten soil series and analyzed for total (nitric acid digestion) and plant-available P (ammonium acetate). Results show that available P did not tend to vary significantly with depth, but there were some significant differences among series. Total soil P tended to decrease with depth and was significantly correlated with available P and organic matter content. Results suggest that a more detailed delineation of soil-landscape variability and P levels in floodplain areas could be important for improving P management in the corridors.