National Geographic magazine recently did an in-depth article on what’s threatening the health of the five Great Lakes. The magazine is read by 3.5 million U.S. readers and in it no-till was blamed for the poor water quality and algae blooms that are choking the life out of Lake Erie. 

While the Lake Erie water quality situation is complicated, condemning no-till doesn’t make sense due to the limited amount of no-till used in the major watershed around Toledo, Ohio.

No-till gained popularity in the 1990s as a way to improve Lake Erie’s water quality, but now the article’s author maintains it has had the opposite effect due to high phosphorus (P) concerns. Admitting that a reduction in moldboard plowing in northwestern Ohio dramatically reduced soil erosion, he argues that applying P close to the soil surface with no-till leads to an unfortunate situation. He makes the argument that no-till leads to an overload of P in Lake Erie, causing  poor water quality and more severe algal blooms.

In addition, the author blames northern Ohio growers for little interest in cover crops, which would reduce the flow of nutrients that fuel the algal blooms. While stating that more cover crops could be a game-changer for the health of Lake Erie, he doesn’t mention that 81% of no-tillers use cover crops compared to maybe 8% for the general farm population.

So where did National Geographic mislead their readers in blaming no-till for Lake Erie’s on-going water concerns? That’s the question we asked retired Ohio State University ag engineer Randall Reeder, Indiana conservation tillage consultant Hans Kok and recently retired Indiana NRCS soil health specialist Barry Fisher. Here’s a summary of their thoughts.

1. Their first mistake in condemning no-till was to rely on inaccurate data collected 20-30 years ago by scientists at Ohio’s Heidelberg University that ignored the fact that less than 10% of the fields in the watershed were continuously no-tilled. Instead, the most common tillage practice was chisel plowing after soybean harvest before planting corn in a tilled field. Only after corn harvest were the fields left undisturbed until no-tilling soybeans the following spring. 

Growers routinely surface-applied P and potassium (K) every 2 years prior to chisel plowing, leaving P and K particles within 1-2-inches of the soil surface. Chisel plowing dramatically increased the runoff flowing into Lake Erie, compared to no-till, which had almost no effect on P increases in field runoff.

2. It’s a complex issue, but with less than 15% true no-till in the watershed today, it’s not the cause of the lake’s poor water quality. 

The real culprit is poor soil health, caused by degraded soil function and poor soil aggregate stability. The resulting poor infiltration results in high runoff due to high P concentrations within 2 inches of the soil surface and continued surface application of P and manure. 

3. Most of the P in Lake Erie comes from streambank erosion rather than no-till. Even if farmers didn’t apply

4. USDA Agricultural Research Service trials in northwestern Ohio found tile lines are responsible for half of the dissolved P leaving area fields. By injecting P and K, farmers could tie these nutrients to soil particles and reduce the opportunity for nutrient escape. 

5. While most research shows cover crops help reduce P loss, a recent study from Kansas State University shows cover crops used with no-till  reduces the amount of dissolved reactive P (DRP) in runoff. This means total P levels should drop dramatically with no-till and cover crops even with the heavy clay soils farmed around Lake Erie. Runoff from tile drains in Indiana and Ohio research shows nitrogen (N) runoff can be almost eliminated with covers, yet maybe not so much with phosphorus.

With the Lake Erie fishing and tourist industry at least five times larger than agriculture in the area, environmentalists anticipate that growers will be regulated with programs more restrictive than even in the Chesapeake Bay. 

To put it bluntly, the National Geographic article is totally inaccurate with its condemnation of no-till in adding P-laden sediment to Lake Erie. Instead, the solution requires a soil health improvement approach that includes the use of more continuous no-till, additional cover crop acres and an improved fertilizer/nutrient management system.