Evaluating the 4R Nutrient Stewardship Concept and Certification Program in the Western Lake Erie Basin


29 Apr 2016

2015 Annual Interpretive Summary

The increase in harmful algal blooms in Lake Erie since the mid 1990s is correlated with an increasing trend in dissolved phosphate loading. A considerable proportion of this dissolved phosphate comes from cropland. This multi-disciplinary research project, initiated in July 2014, aims to understand and quantify the water quality benefits of 4R (right source, rate, time, and place) initiatives in the Western Lake Erie Basin (WLEB). The 4R Certification Program by January 2016 had 25 retail locations certified, reaching more than one million acres in the WLEB.

Three more edge-of-field monitoring sites were instrumented for tile drains and surface runoff in 2015: two in Wood county, Ohio, and one in Steuben county on the Ohio-Indiana border. Each of the sites have paired fields for evaluation of specific 4R practices. An observation from 2014, from a paired site near the WLEB, showed a five-fold reduction in dissolved P loss in tile drain discharge when applied P fertilizer was incorporated into the soil rather than left on the soil surface.

River monitoring of dissolved P concentrations revealed high vulnerability to weather, particularly rainfall. The spring 2015 loading of dissolved P was the highest ever recorded, owing to June-July rainfall amounts and river flows that also exceeded records.

In the modeling components of this project, the Soil-Water Assessment Tool (SWAT) is being adapted to the Maumee, Cedar-Portage and Sandusky watersheds. Project scientists are working to improve its representation of tile drainage and dissolved P. The Western Lake Erie Ecosystem Model (WLEEM) has been calibrated using available data from 2008-2014 for western Lake Erie nutrient concentrations and Microcystis algal bloom biomass. Next steps include investigating: 1) internal lake resuspension of sediment P, 2) impact of invasive mussels on P cycling, and 3) impact of climate change.

In the socio-economic component of this project, a survey of producer 4R practices was launched in December 2015. Results are anticipated by April 2016. The triple bottom line analysis of costs and benefits is being finalized by a Ph.D. student. Initial assessment of public "willingness to pay" for P loading reductions suggest that program benefits are very large in comparison to agri-retailer costs related to 4R certification.

The outreach component of the project includes two websites (http://4rcertified.org/research/ and http://research.ipni.net/project/IPNI-2014-USA-4RN09). In 2015 participating project scientists gave 47 presentations and published 3 scientific papers related to this project. By collaborating across disciplines, participating scientists noted that they have gained appreciation for the relevance of disciplines other than their own to producer decision making. The work of this project over the next several years will continue to receive widespread appreciative attention.