A Focus on Dissolved Phosphorus: from Cropland to Lake Erie

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

Research on Cropland Soils

A BMP Toolbox

Tributary Loading Trends

Bioavailable Phosphorus Loading

Maumee Bay and Western Lake Erie Studies

Links to Related Studies

  1. Final Report of the Ohio Lake Erie Phosphorus Task Force
  2. Final Report of the research synthesis team