422-4 Phosphorus Contribution from Eroding Streambank Soils of Vermont's Lake Champlain Basin.

Poster Number 1238

See more from this Division: SSSA Division: Soil & Water Management & Conservation
See more from this Session: Soil Erosion and Runoff: Impacts on Productivity and Environmental Quality

Wednesday, November 18, 2015
Minneapolis Convention Center, Exhibit Hall BC

Donald S. Ross1, Eulaila Ishee2, Kerrie Garvey2 and Rebecca R. Bourgault2, (1)Jeffords Hall Rm 260, University of Vermont, Burlington, VT
(2)University of Vermont, Burlington, VT
Poster Presentation
  • SSSA_15_Eulaila_poster_11-8-15.pdf (2.6 MB)
  • Abstract:
    Streambank erosion is an important contributor to sediment and nutrient export. This study determined total P (TP), soil test P (Modified Morgan’s, MM-P), and the degree of phosphorus saturation (DPS) in eroding riparian soils along four Lake Champlain Basin stream corridors. We investigated the relationship between these data and soil texture and with a series of GIS-derived landscape metrics. We also quantified the potential P load from eroding streambanks using remote sensing. Soil samples were taken from 76 erosion features to a depth of 90 cm on four streams in Chittenden County, Vermont. Mean concentrations of TP and MM-P were similar among the watersheds and through depth. Neither TP, MM-P, nor DPS were well related to texture. Metrics from available spatial databases for parent material, soil series, and landscape position were somewhat useful in predicting TP and MM-P. Eroding streambank soil from 2004-2007 in the four streams was estimated to contain from 0.5-3.9 Mg of TP and 1.4-10.9 kg MM-P. The mean DPS in each watershed was <18% and, along with low MM-P concentrations, suggests that eroded streambanks may act as sinks rather than sources of P. The portion of total non-point P export potentially contributed by streambank erosion ranged from 6% in the stream with the lowest erosion rate to 30% in the stream with the highest erosion rate. Based on TP values, the P contribution of these streambanks could be considerable and more information is needed on their actual contribution to bioavailable P in receiving waters.

    See more from this Division: SSSA Division: Soil & Water Management & Conservation
    See more from this Session: Soil Erosion and Runoff: Impacts on Productivity and Environmental Quality