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ARS Home » Midwest Area » West Lafayette, Indiana » National Soil Erosion Research Laboratory » Research » Research Project #437760

Research Project: Assessing Legacy Phosphorus losses from Fields and Watersheds in the Western Lake Erie Basin

Location: National Soil Erosion Research Laboratory

Project Number: 5020-12130-004-007-I
Project Type: Interagency Reimbursable Agreement

Start Date: Mar 1, 2020
End Date: Sep 30, 2024

The overall objective of the research is to utilize a multidisciplinary approach that includes analysis of an extensive edge-of-field dataset, laboratory experiments, and field to watershed scale assessment to better understand the delivery of legacy phosphorus (P) to Lake Erie and to provide improved recommendations for P management in the Western Lake Erie Basin (WLEB).

The research will consist of five different approaches for better understanding the loss of legacy P: 1. Estimate the relative contributions of recently applied and legacy P to edge-of-field P loading using data analysis techniques and an extensive dataset from 46 agricultural fields located in the WLEB and surrounding region. 2. Quantify P desorption from agricultural soils and ditch sediments in flow-through laboratory experiments to determine the kinetics of legacy P loss as a function of soil test P concentration and flow rate. 3. Determine the effect of a P ‘hotspot’ on P concentration and loading at the field and watershed scale by building up soil test P levels within a small, select area of each. 4. Assess the utility of phosphate isotopes to distinguish between recently applied and legacy P sources in laboratory soil column experiments and potentially employ at field and/or watershed scales. 5. Examine the fate of dissolved and particulate phosphorus in agricultural drainage ditches through laboratory and field experiments.