Water Resources Research Act Program

Details for Project ID 2006VT27B

Phosphorus availability from the soils along two streams of the Lake Champlain Basin: mapping, characterization and seasonal mobility

Institute: Vermont
Year Established: 2006 Start Date: 2006-03-01 End Date: 2008-02-29
Total Federal Funds: $23,000 Total Non-Federal Funds: $227,162

Principal Investigators: Donald Ross, Joel Tilley

Project Summary: Nonpoint source phosphorus (P) inputs into lakes and streams can be a major source of nutrient loading. A critical need is a better understanding of the relative importance of various P sources (e.g. sediment from streambank erosion, runoff from agricultural fields, or release from aquatic sediments). The ability to predict P input from erosion is limited by a lack of soils data and outdated soils mapping. We will perform an extensive remapping, soil sampling and P analysis of the floodplain areas of two Vermont streams in the Lake Champlain BasinLewis Creek and Rugg Brook. Results will include a new digital soils map of the stream corridors and a data layer that includes total P content and a range of availability indices. We will also determine the transferability of results and the effort needed to provide updated map layers for other stream reaches in Vermont. Intensive, site specific soil studies will be carried out on an area along each stream where restoration projects are planned or underway. These studies will provide more detailed soils mapping and characterize the spatial variability of soil P. Results from these sites will be used to both inform the project managers and to determine the adequate scale necessary for soil P data layers. Field and laboratory studies will also determine P release potential of sediments and soils under reducing conditions on samples from critical source areas including eroded sediments, stream sediments and frequently flooded riparian zones. Results from these experiments will determine the likelihood of additional P release from sediments under oxygen-limiting environments. Geomorphic data from Lewis Creek will be used, along with the new soils map layers, to develop a conceptual model of P transport and storage in the watershed. Our research will develop and refine relationships between soil P fractions and produce simple predictive models of total and potentially mobile P. This will be a collaborative effort between University researchers, NRCS soil specialists and practitioners. Results will enhance our ability to quantify the effects of stream restoration and other best management practices on the control of P transport.