RT Journal Article SR Electronic T1 Soil and landscape influences on native riparian phosphorus availability in three Lake Champlain Basin stream corridors JF Journal of Soil and Water Conservation FD Soil and Water Conservation Society SP 1 OP 7 DO 10.2489/jswc.67.1.1 VO 67 IS 1 A1 E.O. Young A1 D.S. Ross A1 C. Alves A1 T. Villars YR 2012 UL http://www.jswconline.org/content/67/1/1.abstract AB The ability to rank riparian soils by native phosphorus (P) concentration could help prioritize riparian management practices aimed at reducing P loading from streambank erosion. The objective of this study was to explore the relationship between riparian soil variability and native P availability in three riparian corridors in northwestern Vermont. In the first study, two sites along tributaries of Lake Champlain were remapped at a high resolution (1:5000) by the USDA Natural Resources Conservation Service in 2006. After the remapping, multiple profile samples were taken from each series and were analyzed for total P (TP) and Modified Morgan extractable P. In a second study, 27 soil characterization pedons were sampled along three riparian corridors (Lewis Creek, Rugg Brook, and Rock River) to capture a broader range of parent material and P content. These samples were analyzed for particle size separates (sand, silt, and clay content), TP, and oxalate extractable P. Results showed a strong relationship between soil series variation (e.g., texture and drainage differences) and native P concentration. The first study revealed that both Modified Morgan extractable P and TP were lower in the coarser-textured, well drained soil series compared to the finer-textured soils. In the second study, native P concentrations (TP and oxalate extractable P) were also significantly greater in the finer-textured soils. The ratio of oxalate extractable P to TP decreased strongly with increasing sand content (r2 = 0.69), indicating that the finer-textured soils had a greater fraction of potentially desorbable P. Texture was a good indicator of native P concentrations across a wide range of soil properties, suggesting that accurate soil maps will be an important tool for indexing the native P status along riparian corridors in the Lake Champlain Basin region.