Examining phosphorus contributions from alluvial soils - a comparison of three Vermont, U.S.A. River corridors

摘要

The distribution of soils in the floodplain environment is highly complex. The often extreme spatial variability of alluvial soils, in both the vertical and lateral dimensions, creates challenges to adequately capture the range in P values found in the riverine environment. It is important to take samples from a wide range of geographic locations and soil series. Lack of data on phosphorus levels in floodplain soils impede research efforts aimed at reducing the rate of P delivery to Lake Champlain, Vermont, U.S.A. Once estimates for sediment loading rates have been derived, it is crucial to know the P values of the eroded material. Results from soil sampling projects in 2007 and 2008 along the Rock River, Rugg Brook / Mill River and Lewis Creek corridors have greatly expanded the soil database. Profile characterization gives a wealth of chemical and physical data for 28 sites. Preliminary results highlight some important differences between the three study areas. Levels of soluble P, which approximate concentrations of P in the soil solution, the mobile fraction, were higher in the Rock River samples. Across all sites, percent carbon and silt content tend to be correlated with higher P values.