Farmers Battle Phosphorus Runoff Fueling Lake Erie Algae Blooms

Growers in northwest Ohio work to keep nutrients on their fields and out of the lake.

Apr. 18, 2026 at 5:55am

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A highly textured, abstract painting in earthy tones of green, brown, and blue, featuring sweeping geometric shapes, concentric circles, and precise botanical spirals, conceptually representing the complex interplay of natural and agricultural systems that impact water quality in Lake Erie.An abstract visualization of the intricate natural and human-driven processes that govern nutrient flows from farmland into Lake Erie, fueling both agricultural productivity and harmful algal blooms.Toledo Today

For years, farmers in northwest Ohio have faced claims that phosphorus runoff from their fields is the primary cause of the extensive algae blooms that develop each summer in western Lake Erie. Researchers have found that factors like low soil pH and certain metals are causing glyphosate to release phosphorus from the soil, leading to about 25% of the dissolved reactive phosphorus runoff in the Maumee watershed that feeds into the lake.

Why it matters

The U.S. and Canadian governments have called for deep cuts in phosphorus runoff from farms and other sources into Lake Erie, where an overload in recent years has fed harmful algae blooms that have fouled drinking water and killed fish. Farmers in the region are under pressure to find ways to keep nutrients on their fields and out of the lake.

The details

No-till farmers like Blake Vince have been incorporating cover crops and multi-species cover mixes to protect their soil and prevent nutrient runoff. Other growers are working to keep good records on manure and fertilizer applications as new regulations in Ohio's Senate Bill 1 limit surface applications in the western Lake Erie basin. Researchers have also found that widespread drought, like in 2012, can exacerbate the lake's 'dead zones' by fueling algae growth.

  • For years, growers in northwest Ohio have battled claims about phosphorus runoff.
  • In 2012, a widespread drought was associated with Lake Erie's largest dead zone since the mid-1980s.

The players

Blake Vince

A Nuffield scholar and no-till farmer in Merlin, Ontario who has incorporated cover crops and multi-species mixes to protect his soil and prevent nutrient runoff.

Joe Nester

The owner of Nester Ag, who discusses why growers are seeing more problems with phosphorus runoff and what they can do to keep nutrients from leaving their fields.

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What they’re saying

“We started no-tilling in 1983 and are still on that path today. For years, we've incorporated cover crops and now we're using multi-species cover crops to protect the soil.”

— Blake Vince, Nuffield Scholar and No-Till Farmer

“Low soil pH and certain metals are causing glyphosate to release phosphorus from the soil, which is responsible for about 25% of dissolved reactive phosphorus runoff in the Maumee watershed.”

— Joe Nester, Owner, Nester Ag

What’s next

Ohio lawmakers have passed Senate Bill 1, which includes new rules designed to reduce phosphorus runoff into Lake Erie's western basin. No-till farmers in the region will need to closely track their manure and fertilizer applications to comply with the new regulations.

The takeaway

Farmers in the Lake Erie watershed are under increasing pressure to find ways to keep nutrients on their fields and out of the lake. Innovative no-till practices like cover cropping, as well as careful record-keeping, will be critical to reducing phosphorus runoff and preventing harmful algae blooms.