The NCWQR’s tributary loading program has documented large increases in the movement of dissolved reactive phosphorus (DRP) from Northwestern Ohio cropland through streams and rivers into Lake Erie. These increases began in the mid-1990s and coincide with increasing problems of excessive algal growth in the Western Basin of Lake Erie. The deliberations of the Ohio Lake Erie Phosphorus Task Force concluded that these increases in DRP loading to Lake Erie were contributing to the algal problems and that programs to reduce DRP loading should be developed.
While the NCWQRs research programs have largely focused on studies of the transport of phosphorus and other nutrients, sediments and pesticides at a set of river monitoring stations throughout Ohio, in recent years our studies have extended onto cropland itself to help determine the causes of the increased DRP runoff. Our cropland and soils studies include measurements of phosphorus stratification in area soils and relationships between soil testing methods and water testing methods. We have assembled a BMP “toolbox” to help guide farmers and their advisors in reducing DRP export from cropland. Our recent research has also extended out into Maumee Bay and the Western Basin of Lake Erie to help quantify linkages between agricultural nutrients that move into the lake during storm events and subsequent excessive algal growth in the Lake. This section of our website collects these various research and monitoring efforts related to dissolved phosphorus into a single focus area.
Problem Introduction
- Dissolved Phosphorus from Cropland Runoff: Why is it such a Big Problem?
This issue of NCWQR News and Notes provides a problem overview - A Comparison of Particulate and Dissolved Phosphorus
This table summarizes the differences between particulate and dissolved phosphorus.
Research on Cropland Soils
- Phosphorus Stratification in Soils: Background and Examples
This issue of NCWQR News and Notes provides an introduction of phosphorus stratification in soils. - The extent of phosphorus stratification in cropland soils of the Sandusky Watershed
This report summarizes data from 761 fields in the watershed with stratified testing for 0-2 inch and 2-8 inch strata collected during 2009 and discussed in GLPF Grant Team Meeting #3. - Phosphorus stratification in relation to agricultural production practices and the soil resource base in the Sandusky Watershed.
This report integrates soil stratification data with supplementary information for each field receiving stratified soil testing and was discussed in GLPF grant, Team Meeting #3. - Comparisons of phosphorus concentrations in water and in soils/sediments along a gradient from cropland, through rivers to the Western Basin of Lake Erie
This report introduces applications water analyses methods directly to dilute aqueous soil suspensions and compares results from soils, rivers and lake waters. - Applications of Water Testing Methods Directly to Soils
To gain insights into the relationships between soil test levels and phosphorus forms in rivers, we applied water chemistry methods directly to dilute soil suspensions of soils of known soil test levels. This 2011 document represents the final report (Part 3) of our grant from the EPA Great Lakes National Program Office for the study of bioavailable phosphorus transport into Lake Erie.
A BMP Toolbox
- A BMP Toolbox for Reducing Dissolved Phosphorus Runoff from Cropland to Lake Erie
This toolbox was prepared by John Crumrine as a part of our GLPF grant to address DRP issues in the Lake Erie Watershed. - Summary of Participant Comments on BMP Toolbox Content, Toolbox Presentation and Related Dissolved Phosphorus Issues.
The BMP Toolbox was the subject of detailed discussions during GLPF Team Meeting # 4. This paper summarizes those discussions.
Tributary Loading Trends
- Record Amounts of Dissolved Phosphorus Hit Lake Erie
This issue of NCWQR News and Notes describes the record spring (April through June) loads of DRP that moved from the Maumee River into Lake Erie in 2010. - Record Amounts of Dissolved Phosphorus Hit Lake Erie, Technical Supplement
This News and Notes issue provides additional information regarding the record spring loads of DRP that entered Lake Erie from the Maumee River in 2010.
Bioavailable Phosphorus Loading
- Trends in Bioavailable Phosphorus Loading at River Monitoring Stations
This 2011 report summarizes our studies of the trends in bioavailable particulate and dissolved phosphorus in major tributaries to Lake Erie. This represents Part I of our EPA/GLNPO supported grant or Bioavailable Phosphorus Transport into Lake Erie. - Trends in Bioavailable Phosphorus Loading to lake Erie
This report summarizes work done under Erie Protection Fund Grant #SG 315-07. - Bioavailability of Phosphorus from Contemporary Sewage Treatment Plant Effluents
This study was completed by the Northeast Ohio Regional Sewer District at three Cleveland area sewage treatment plants. It was complete as Part 4 of Heidelberg’s GLNPO grant for studies of bioavailable phosphorus loading to Lake Erie.
Maumee Bay and Western Lake Erie Studies
- Relationships between Stream Flow and Water Chemistry in River Mouth Systems: Examples from the Maumee River
This issue of NCWQR News and Notes introduces our studies of storm runoff water from the Maumee Watershed as it moves through the lower Maumee River, Maumee Bay and the Western Basin of Lake Erie. - Lagrangian Analysis of Bioavailable Phosphorus Transport from Tributary Loading Stations into Nearshore Zones
This document is our report to the EPA/Great Lakes National Program Office for Part 3 of our research project on the transport of bioavailable phosphorus to Lake Erie. It expands on the above issue of NCWQR News and Notes.
Links to Related Studies
- Final Report of the Ohio Lake Erie Phosphorus Task Force
http://www.epa.ohio.gov/portals/35/lakeerie/ptaskforce/Task_Force_Final_... - Final Report of the research synthesis team
http://go.osu.edu/ts-060