Eagle Creek BMP Research

A recent September 2026 U.S. Geological Survey (USGS) study evaluated agricultural best management practices (BMPs) at an edge-of-field site in the Eagle Creek watershed near Findlay, Ohio. The project started in 2010, with the U.S. Geological Survey (USGS), Great Lakes Restoration Initiative, and the Natural Resources Conservation Service (NRCS) working together. These three government agencies identified farm fields in priority watersheds—watersheds critically important to Great Lake health.

Intensive BMP’s were implemented in five States to test the efficacy of best management practices, also referred to as agricultural conservation practices, to reduce sediment and nutrient runoff on agricultural fields. These fields were chosen as representatives of the priority watersheds because their farming practices and geographical conditions were common among farms in those watersheds.

A farm site located near Findlay, Ohio, in the Eagle Creek watershed used two conservation practices, cover crops (Natural Resources Conservation Service practice standard 340) and variable rate technology (VRT; Natural Resources Conservation Service practice standard 590), which represent common practices in the Maumee priority watershed. This study monitored surface runoff and subsurface tile runoff at the Eagle Creek watershed site.

The U.S. Geological Survey (USGS) tracked data from October 2012 to September 2020. USGS Scientific Investigations Report 2026–5037, "Evaluation of Best Management Practices at an Edge-of-Field Site in the Eagle Creek Watershed, Ohio, 2012–20" gives the results.

The primary data gave breakdowns for total phosphorus (TP), particulate phosphorus (PP), dissolved reactive phosphorus (DRP), and suspended sediment (SS). The study focused on the distinction between surface runoff and subsurface tile runoff, categorized by storm size relative to the 85th percentile of peak discharge (large runoff events).

Particulate Phosphorus (PP) is P attached to soil particles, while DRP is the soluble fraction of P that causes most of the harmful algae blooms in Lake Erie. Total phosphorus (TP) is both PP and DRP combined. Suspended sediment (SS) are the tiny particles of soil that erode off soil and remain or float in water runoff. All contribute to water quality problems in surface water, especially in Lake Erie.

Cover crops were applied in fall of 2016, 2017, and 2018, coinciding with VRT applications. High peak runoff events disproportionally affected nutrient concentrations and loads in runoff. A threshold of the 85th percentile of the peak discharge was chosen to assess the effect of cover crop and VRT nutrient application on nutrient mitigation at each gage. Runoff events below the 85th percentile were considered small, and runoff events over the 85th percentile were considered large.

During the cover crop season, the reductions in phosphorus and sediment loss were most pronounced between November (planting) and March (termination). During these months, the cover crops anchored what would otherwise be bare soil, preventing high-concentration surface runoff. For the 85th Percentile Threshold**,** high peak runoff events disproportionally transport the majority of annual nutrient and sediment losses. Because the cover crop and VRT combination failed to alter loads during these large events, the data suggests that edge-of-field practices must be paired with structural BMPs (like filter strips or retention structures) to achieve broader watershed-scale reductions. Here were the Key Findings:

During smaller runoff events (below the 85th percentile of peak discharge), implementing cover crops and VRT significantly lowered surface-runoff concentrations and loads for suspended sediment and phosphorus fractions. Subsurface tile runoff parameters showed no statistically significant differences during these smaller events. Neither surface nor subsurface runoff parameters showed measurable water-quality improvements during the largest storm events (above the 85th percentile). The research highlights that while precision farming and cover crops help during minor flushes, complementary practices targeting high-volume, peak flow events are needed for broader watershed protection. These results indicate cover crops and VRT may improve water quality during small runoff events, but additional best management practices that mitigate large runoff events may lead to greater water-quality improvement given the contribution of large events to higher overall losses.

In a completely separate research study, for over forty years, research scientist thought that house plant leaves were cleaning our air of pollutants. However, now we know that it was actually bacteria in the soil that was doing most of the work. In the 1980’s, NASA sealed houseplants in a box, pumped in formaldehyde, and measured how fast the air becomes clean. Peace lilly, spider plants and pothos were the best. Then recently, a Korean team repeated the study, putting the whole plant, just leaves, and just soil in a chamber. During the day, the leaves (surface covered by bacteria) and the pot of soil cleaned the air. At night (dark), the pot of soil and bacteria did 11X more work. It’s bacteria or microbes that clean pollutants out of air.