Seasonal Influence on Phosphorus (P) Sorption Capacities in Streams and Ditches in Eagle Creek Watershed

Authors: WILLIAMS, C - PURDUE UNIVERSITY; JOERN, B - PURDUE UNIVERSITY; Smith, Douglas; BOWLING, L - PURDUE UNIVERSITY; LEMBI, C - PURDUE UNIVERSITY

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 9/4/2007
Publication Date: 11/5/2007
Citation: Williams, C., Joern, B., Smith, D.R., Bowling, L., Lembi, C. 2007. Seasonal Influence on Phosphorus (P) Sorption Capacities in Streams and Ditches in Eagle Creek Watershed. American Society of Agronomy Annual Meeting Abstracts. November 4-8, 2007, New Orleans, LA. 2007 CDROM.

Interpretive Summary:

Technical Abstract: Internal P loading from sediments to waterbodies may be a significant source of P and may prevent the attainment of surface water nutrient criteria developed by the USEPA. Our objectives were to 1) relate surface water P concentrations to sediment P, 2) determine if differences in land use were related to ditch and stream water P concentrations and sediment P status and 3) determine if seasonal differences were associated with water and sediment P concentrations in the ditches and streams that contribute to a major drinking water reservoir for the city of Indianapolis, IN. Findings showed that there was often a relationship between sorption capacity of the sediment and water column P, but the relationship was not consistent. The potential mass of P that could be sorbed by the sediment before soluble P exceeded the proposed EPA nutrient criteria limit (0.076 mg P/L) was greatest for August samples. Extractable P (20 mM CaCl2) in sediment was consistently below the proposed EPA nutrient criteria for all samples and sampling months. This information is beneficial in quantifying P dynamics in different land use types.