Impacts of Water and Sediment Control Basins (WASCoBs) on Water Quality Near Atterberry, Illinois

Author

Sara Lambert, Southern Illinois University CarbondaleFollow

Date of Award

12-1-2023

Degree Name

Master of Science

Department

Forestry

First Advisor

Schoonover, Jon

Abstract

The environmental impacts of agricultural non-point source pollution, due in part to the intensification of agriculture to meet the nutritional needs of a growing population, indicate a need for the further implementation of Best Management Practices (BMPs) that can mitigate soil erosion and reduce the export of sediment and nutrients to receiving waters. Water and Sediment Control Basins (WASCoBs) and cover crops are both considered effective in-field BMPs that have been utilized by landowners to reduce soil and nutrient losses from fields. While each of these BMPs has been individually researched for their impacts on soil and water quality, there is little existing research that examines the impact of WASCoBs paired with cover crops on water quality. This study compared four sub-watersheds on the same field near Atterberry, Illinois: 1) a basin drained by a WASCoB, 2) a basin drained by a WASCoB and planted with a cover crop, 3) a basin drained by an ephemeral gully and planted with a cover crop, and 4) a control basin drained by an ephemeral gully. Runoff samples were collected from these watersheds and analyzed for total phosphorus, dissolved reactive phosphorus (DRP), ammonium-nitrogen, nitrate-nitrogen, and total suspended solids (TSS). Nutrient and sediment concentrations were used along with the discharge and duration of runoff events in order to determine event loads for each watershed. The WASCoBs utilized in this study were able to trap 97.3-99.2% of total phosphorus, 84.3-94.4% of DRP, 51.4-78.6% of ammonium-nitrogen, 11.8-56.3% of nitrate-nitrogen, and 98.68-99.21% of TSS. The cover crop treatments in this study did not show a significant impact on water quality, which was likely attributed to poor establishment of the cover crop. These results suggest that early planting is critical for maximizing cover crops establishment and benefit. Reductions in nutrient and sediment loads in this study suggest that WASCoBs have the potential to reduce the discharge of nutrients and sediment to waterways, indicating that their continued implementation may help to accomplish water and soil conservation goals.