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.

The agriculture community is faced with new challenges to increase food production on a limited amount of suitable land to keep up with the growing population. Fertilizers and intensive cropping are needed to meet food demand, but these practices contribute to environmental degradation due to nutrients and sediment leaving fields and entering waterbodies. Non-point source (NPS) pollution from agriculture has been scrutinized for significantly contributing to eutrophication and hypoxic dead zones. To reduce the harmful impacts of NPS pollution from agriculture, producers and land users have implemented in-field and edge-of-field Best Management Practices (BMP). Water and Sediment Control Basins (WASCoBs) are an example of an in-field BMP that has helped reduce erosion and sediment loading of receiving waters. Cover crops are another in-field BMP that have been used to mitigate erosion and nutrient leaching. The impacts of WASCoBs paired with cover crops on water quality, specifically nutrient loading, is lacking in the current literature and was the focus of this research. Our study site was located in Menard County near Atterberry, IL. The farm had relatively steep topography (5-18% slopes) and suffered from severe gully erosion. In 2018, the Natural Resource Conservation Service (NRCS) partnered with the landowner and installed a series of WASCoBs to address the erosion issues. Along with the NRCS and landowner, we worked with the Illinois Farm Bureau (IFB) to investigate the impacts of WASCoBs and cover crops on nutrient and sediment runoff, hydrology, and crop yields.Four sub-watersheds were included in the study: 1) a 1.5-hectare basin treated with a WASCoB; 2) a 1.4-hectare basin treated with a WASCoB and a cover crop; 3) a 0.2-hectare gully drained watershed treated with a cover crop; and 4) a control, 3.8-hectare gully-drained watershed. ISCO automated water samplers collected runoff from storm events in a time-weighted composite sampling regime. The measured water quality parameters were total suspended solids (TSS), ammonium-nitrogen (ammonium-N), nitrate-nitrogen (nitrate-N), dissolved reactive phosphorus (DRP), and total phosphorus (TP). The WASCoB treatment reduced TSS by 98.5-99.8%, TP by 83.8-97.4%, ammonium-N by 42.3-82.9%, and nitrate-N by 32.0-59.6%, respectively. Cover crop impacts on the water quality parameters were not detected, due to poor gemination of the annual rye cover crop. The water quality improvement WASCoBs are a potential tool for farmers and land managers to reduce loading of nutrients and sediment to receiving waters.