COLUMBUS, Ohio - Ohio has struggled for decades to curb the phosphorus pollution that fuels harmful algal blooms and threatens drinking water supplies. A new research-driven partnership in Hardin County suggests a practical, farmer-driven approach can deliver measurable water quality improvements faster than expected without sacrificing agricultural productivity.

Results from the Pilot Watershed Project, a five-year research effort led by The Ohio State University College of Food, Agricultural, and Environmental Sciences (CFAES), shows a 38% reduction in dissolved reactive phosphorus (DRP) in the Shallow Run watershed since 2024. This is especially notable as no other western Lake Erie watersheds have demonstrated such large reductions in the nutrient that drives algal blooms in Lake Erie.

That progress comes while participating farms maintain strong crop production and soil health outcomes, said Jay Martin, project lead and Distinguished Professor in Ecological Engineering in the CFAES Department of Food, Agricultural and Biological Engineering.

"This project demonstrates that it's possible to meet watershed water quality targets while sustaining agricultural production," Martin said. "Working closely with the agricultural community, we've increased adoption of conservation practices beyond previous levels and achieved real water quality improvements."

The stakes are high.

DRP contributes to harmful algal blooms that threaten public health, fisheries and drinking water supplies across northwest Ohio. In 2014, toxic blooms left 400,000 Toledo residents without safe tap water for days. Agriculture, which dominates the Maumee River watershed, is a key part of the solution but one that requires data-backed, farmer-supported strategies to succeed at scale.

If unaddressed, phosphorus pollution threatens Ohio's $14 billion corn and soybean industries, Lake Erie fisheries valued at $800 million annually, and drinking water for more than 11 million people. Shallow Run's early results suggest that targeted investments and coordinated conservation efforts could help meet H2Ohio 's goal of a 40% phosphorus reduction across the Western Lake Erie Basin without sacrificing yields or farm income. H2Ohio is a collaborative, long-term water quality initiative launched by Ohio Gov. Mike DeWine in 2019.

The Pilot Watershed Project focuses on 5,216 cropland acres in the Shallow Run watershed, a tributary of the Blanchard River that ultimately feeds into Lake Erie.

Backed by $18.7 million in support from the U.S. Department of Agriculture's Natural Resources Conservation Service; the Ohio Department of Agriculture (ODA); CFAES; and other universities, agribusinesses, and nonprofit partners, the project demonstrates how focused resources and farmer engagement can deliver results. Project researchers also tested a range of practices designed to reduce phosphorus loss while supporting productivity, including restored wetlands, buffer strips, drainage water management and phosphorus filters installed at high-loss locations.

In three years, Shallow Run farmers have sharply increased conservation practices. Today, 80% of acres have nutrient management plans, compared to an estimated 50% before the project began. Half of the acres are planted with cover crops now, up from just 10%, and one-third now apply phosphorus below the soil surface - triple the county average.

Compared with a nearby control watershed, Potato Run - where DRP increased by 47% over the same period - the Shallow Run reductions offer strong evidence that wide-scale conservation works when farmers are empowered to lead.

Martin attributes the success to a collaborative approach that centers on local priorities and practical support.

"Listening to farmers and other local partners to understand how practices impact operations economically and logistically is key," he said. "That's how we can overcome barriers to adoption and build durable change."

Participating farmers receive higher-than-standard payments through a combination of H2Ohio and Pilot Watershed Project funds. These include $60 per acre for cover crops and at least $25 per acre for subsurface placement, with additional incentives for nutrient management and buffer or wetland installations.

Martin also credits the Hardin County Soil and Water Conservation District for helping farmers navigate paperwork and enroll in programs. Farmer-focused events like a group fishing trip on Lake Erie help build community and keep momentum going.

The Shallow Run model is already shaping conversations across Ohio. In fall 2025, project researchers hosted tours for state legislators, the ODA, and national journalists from outlets including The New York Times and Los Angeles Times. It was also featured on a recent episode of the Ohio Farm Bureau's statewide water quality podcast.

"This project is about learning what works on the ground and using those lessons to guide policy and investment in other watersheds across Ohio," Martin said.

Ultimately, the goal is to help Ohio meet its phosphorus reduction targets across the 3 million-acre Maumee watershed without compromising the productivity or viability of the farms that support the state's agricultural economy.

"This work is a blueprint," Martin said. "It shows what's possible when farmers lead the way."