Fertilizer Application Patterns and Trends, and Their Implications for Water Quality in the Western Lake Erie Basin

Transcription

1 Fertilizer Application Patterns and Trends, and Their Implications for Water Quality in the Western Lake Erie Basin Prepared by Great Lakes Science Advisory Board Science Priority Committee Fertilizer Application Work Group NOAA, 2015 INTERNATIONAL JOINT COMMISSION COMMISSION MIXTE INTERNATIONALE Canada and the United States Canada et États-Unis

2 Welcome and thank you for your participation Gordon Walker Chair, Canadian Section International Joint Commission

3 J. David Allan* (Co-Chair) Michael Murray* (Co-Chair) Workgroup Members and Reviewers University of Michigan Laura Johnson Heidelberg University National Wildlife Federation Pamela Joosse Agriculture and Agri-Food Canada Tom Bruulsema International Plant Nutrition Institute Joe Kelpinski Patricia Chambers Environment and Climate Change Canada Kevin King Michigan Department of Agriculture and Rural Development U.S. Department of Agriculture, Agricultural Research Service Anne Cook The Andersons Incorporated Andrea Kirkwood University of Ontario Institute of Technology Irina Creed Western University Rebecca Muenich Arizona State University Steve Davis U.S. Department of Agriculture, Natural Resources Conservation Service Jeff Ridal Joe DePinto Independent Consultant Clare Robinson Western University St. Lawrence River Institute of Environmental Sciences Brad Glasman Upper Thames River Conservation Authority Craig Stow National Oceanic and Atmospheric Administration Pradeep Goel Ontario Ministry of Environment and Climate Change Chris Winslow Ohio State University Bob Hecky University of Minnesota Duluth Santina Wortman U.S. Environmental Protection Agency IJC Staff: Matthew Child*, International Joint Commission (Great Lakes Regional Office) Glenn Benoy, International Joint Commission (Canadian Section) Mark Gabriel, International Joint Commission (U.S. Section) * Work group report authors Project Team LimnoTech: John Bratton, Noemi Barabas, Chelsie Boles, Brian Lord, Dan Rucinski, Derek Schlea

4 NOAA, 2017 Purpose of webinar: Review assessment of past, current and possible future nonpoint agricultural runoff of phosphorus into western Lake Erie, and their potential to cause eutrophic conditions and harmful algal blooms Outline recommendations for additional research, monitoring and data needed to implement best management actions to restore health of Lake Erie Questions and Comments

5 Presenters Dr. J. David Allan, Work Group Co-Chair University of Michigan School for Environment and Sustainability Co-author of report Dr. Michael W. Murray, Work Group Co-Chair National Wildlife Federation Great Lakes Regional Center Co-author of report

6 Project Introduction Key Objective: Assess magnitude and relative importance of two broad nutrient sources commercial fertilizer and manure and influence of associated management practices on nutrient loads and their impacts to the western Lake Erie basin (WLEB) NOAA, 2017 Evaluate commercial fertilizer and manure application patterns throughout WLEB (including Huron-Erie Corridor) Review land and nutrient management programs, current monitoring and modelling efforts, and factors influencing nutrient loads to Lake Erie Project team: IJC Science Priority Committee members, working group, and contractor (LimnoTech) Full report: Technical report:

7 Findings and Recommendations: Relative Importance of Different Nutrient Sources No analytical or data analysis methods for distinguishing P loads to lake from commercial fertilizer versus manure Recommendation: Continue emerging research on P source monitoring, field-based monitoring of P loss 2. Estimated overall (elemental P) manure generation and commercial fertilizer application values ( ): 41,687 tonnes (72 percent) for U.S. watershed 16,327 tonnes (28 percent) for Canadian watershed Recommendations: Agencies obtain (e.g. through surveys) commercial fertilizer data at higher temporal and spatial resolution Better quantify all major components of manure generation, management, field application, and associated P loss and impacts

8 Commercial Fertilizer Application Summary Commercial Fertilizer P Application Rate P application declining over past few decades No apparent major changes in application rate over past decade Some areas of elevated application Numerous data/information challenges, e.g.: Type of commercial fertilizer Distinguishing P by type of fertilizer or recent vs legacy Information on farm practices not available publicly at high resolution Data from IPNI NuGIS database, prepared by LimnoTech

9 Manure Production Summary Commercial:manure P ~ 80:20 in U.S. portion, 50:50 in Canadian portion Manure P Production/Area More manure generated, applied in upper watersheds No apparent major changes in manure production since mid-1980 Numerous data/information challenges, e.g.: Information on quantities applied, specific locations Potential for hot spots Less information on non-permitted animal feeding facilities Data from IPNI NuGIS database, prepared by LimnoTech

10 Findings and Recommendations: Relative Importance of Different Nutrient Sources 2 No field evidence of differences in P export for commercial fertilizer vs. manure Sources other than commercial fertilizer, manure appear to be relatively minor (but may have local impacts) Also need to consider crop balance, legacy sources Bast et al. 2009; IPNI Recommendations: Expand source attribution research Evaluate approaches to increasing data availability Expand understanding of location of legacy P (below)

11 Monitoring Western basin of Lake Erie and tributaries are among most intensively monitored parts of Great Lakes basin Monitoring data are critical to diagnosing problems, tracking improvements, and calibrating models There is need for improved integration of monitoring programs across jurisdictions, and enhanced monitoring overall Recommendations: Design and implement an integrated long-term monitoring network for water quality and agricultural practices to support management decisions Develop stable funding mechanisms and institutional stewards for sustained, long-term binational monitoring and data management Full report: Technical report:

12 Conceptualized nitrogen (a) and phosphorus (b) processes in SWAT Modeling Models provide important insights that may not be possible from field observations alone, and can simulate future outcomes of management interventions The Soil and Water Assessment Tool (SWAT) has been particularly helpful in exploring nutrient runoff sensitivity to various drivers and the effectiveness of different management strategies Neitsch et al., 2011 Results suggest wide implementation of mix of strategies is necessary to meet P targets Recommendations: Integrate modeling work and monitoring networks with high-resolution surveys of changing agricultural practices and watershed characteristics to support predictions Continue development of research models at various scales to improve process understanding and simulate alternate management scenarios

13 Additional Factors Influencing Affecting Nutrient Loss Tillage practices Subsurface tile drains Legacy P Climate change Others Factors

14 Tillage Practices Some type of conservation tillage (mulch tillage, seasonal no-tillage, or continuous no-tillage) is in place on the majority (63%) of WLEB cropland Expansion of conservation tillage since the 1990s; while providing other benefits, conservation tillage is considered a contributory factor to DRP export Tillage practices can affect P accumulation in the uppermost soil layer, and may allow soil macropores to form linking soil surface to drain tiles Recommendation: Support research and monitoring into the implications of various tillage practices for P accumulation at the soil surface and P transport through drain tiles, and to explore potential new approaches to minimizing P losses associated with various tillage practices

15 Subsurface Tile Drains Tile drains likely increase conveyance of P through subsurface pathways Tile drainage is extensive, continuing to expand, and not well documented Recommendation: Agencies obtain more current data on tile drainage networks and impact on P form and mass transport, including interactions with tillage practices, fertilizer application, and relative role and rates of tile discharge versus surface runoff of P Smoothed, long-term trend for the DRP/TP concentration ratio in the Maumee River Stow et al Stow et al. 2015

16 Legacy P Stored soil P (legacy P) has accumulated over past decades due to fertilizer application in excess of P removal in harvested crops Recent declines in surface soil P levels suggest drawdown of stored P, consistent with declines in P fertilizer application and in P removal as crop harvest Some legacy P may be mobilized for years to come, including from P-saturated non-agricultural land Recommendation: Agencies collect and regularly update binational data set of phosphorus soil data (including vertical stratification, with consistent protocols for soil test phosphorus)

17 Climate Change Increased river discharge since the 1990s contributes to current elevated TP and DRP loads Should river discharges increase in future years, attainment of target P loads will become more difficult Recommendation: Continue to evaluate climate change impacts on P loads from rivers as a potentially complicating factor influencing determination of (and approaches to meet) target loads Monthly average precipitation for Ohio Region 1 (top) and Maumee River discharge (bottom) for (reprinted with permission from Stow et al Copyright 2015 American Chemical Society)

18 Closing Remarks Management practices may have a greater influence on P delivery to Lake Erie than the type of fertilizer used Broad implementation of a mix of existing BMPs is necessary to reduce P loads Current efforts to improve P incorporation and minimize edge-of-field P loss may lead to wider use of new management practices Recommendations: Continue to promote 4R implementation and other approaches of nutrient management, and expand efforts to evaluate effectiveness Support research and monitoring to improve process understanding and identify management options best able to reduce export of all forms of P

19 Objectives and Key Questions Key Objective: Assess the magnitude and relative importance of two broad nutrient sources, commercial fertilizer and manure, and the influence of nutrient management associated with those major sources on nutrient loads and their impacts to the WLEB. Attempted to address following questions: What are magnitudes of commercial fertilizer use and manure generation and use in WLEB? Are data sufficient to understand relative importance of these sources to phosphorus delivery to WLE? What is extent of best management practices and programs (e.g. 4R nutrient stewardship) in WLEB and what is their effectiveness in managing phosphorus loss to tributaries from major sources? What is extent of existing monitoring programs and are these programs adequate to ascertain the relative importance of commercial fertilizer and manure as phosphorus sources to WLE? What are capabilities of existing models to help ascertain the relative importance of commercial fertilizer and manure as contributors of phosphorus to Lake Erie and also to assess the effectiveness of various management practices? Full report: Technical report:

20 For more information on Fertilizer Application Patterns and Trends, and Their Implications for Water Quality in the Western Lake Erie Basin Contact Matthew Child, Science Priority Committee Secretary Full report: Technical report: Download this webinar at

21 Lake Erie has benefitted from bold action in the past and requires similar bold action today to ensure its health and value to the people of the basin into the future.