Worms And Tile Lines Combine To Create Runoff Problems

USDA researcher warns no-tillers to limit liquid manure application and be ready to dam tile lines

Apr. 18, 2026 at 9:14am

Got story updates? Submit your updates here. ›

A bold, highly structured abstract painting in earthy green, brown, and blue tones, visualizing the complex interaction between earthworm burrows, drainage tiles, and liquid manure runoff in a no-till farming system. The composition resembles a massive, wordless scientific diagram, using sweeping geometric arcs, concentric circular patterns, and precise botanical spirals to convey the structural order and hidden pathways of the soil ecosystem.An abstract visualization of the unseen pathways that can carry liquid manure from no-till fields into nearby waterways, highlighting the need for careful management of nutrient runoff.Coshocton Today

A USDA researcher has found that the combination of earthworm burrows and drainage tiles in no-till fields can increase the risk of pollution to nearby waterways from liquid manure applications. The researcher cautions no-tillers to limit manure applications and be ready to dam tile lines to avoid contamination.

Why it matters

No-till farming practices generally decrease surface runoff, but the researcher's studies show that contaminants can still infiltrate through worm channels and travel to tile lines, which then carry the pollutants to adjacent waterways. This has led to numerous fish kills near the research site.

The details

Martin Shipitalo, a USDA researcher, recommends that no-tillers should not apply liquid manure to their fields when a tile line is flowing. He also advises limiting liquid manure applications to 10,000 to 15,000 gallons per acre, injected at a depth of no more than 8 inches, and being ready to make a dam if there is flow from a tile. Shipitalo's recommendations are based on his studies of runoff at the North Appalachian research farm near Coshocton, Ohio, as well as previous studies.

  • Over a 4-year period, Cooperative Extension Service staffers in Ohio counted 98 fish kills near the research farm tied to the runoff of manure through the tile lines.

The players

Martin Shipitalo

A USDA researcher who has studied runoff at the North Appalachian research farm near Coshocton, Ohio.

North Appalachian research farm

The research site near Coshocton, Ohio where Shipitalo has conducted his studies on runoff and tile lines.

Got photos? Submit your photos here. ›

What they’re saying

“And be ready to make a dam if there is flow from a tile”

— Martin Shipitalo, USDA researcher

The takeaway

This research highlights the importance for no-till farmers to carefully manage liquid manure application to avoid contaminating nearby waterways, even when using no-till practices that generally reduce surface runoff. Monitoring tile lines and being prepared to dam them if needed is a key step to prevent pollution.