- Additional Plants: native plants
- Education and Training: on-farm/ranch research
- Natural Resources/Environment: grass waterways
- Soil Management: nutrient mineralization, soil chemistry
- Sustainable Communities: infrastructure analysis
Agriculture and development can severely alter watershed hydrology, with negative implications for downstream water quality. Bioretention, one of the most common forms of Green Stormwater Infrastructure, can be used to capture and store runoff, allowing treatment in situ through natural vegetative and soil processes. While bioretention is increasingly recommended as a best management practice, there is a growing need to select specific design components based on site and pollutant characteristics. Our research explores the effects of compost and vegetation on the ability of bioretention cells to treat nutrients and total suspended solids (TSS) from runoff a mixed urban/agricultural watershed. In May 2016, three large (111.5 m2) bioretention cells were installed at the University of Vermont Miller Research Complex to treat stormwater from the production area of the farm. Inflow and outflows of the bioretention cells will be monitored to assess nutrient (nitrogen and phosphorus) and TSS concentrations throughout the first growing season post-installation. Experimental treatments of the cells include: unvegetated (control), vegetated, and vegetated with added compost, allowing for an isolation of the variables’ effects on pollutant mass and concentration removal. We will analyze bioretention media samples from five different depths within the cells to determine if there is a difference in the vertical concentration of nutrients, and if so, to what extent it is affected by our experimental treatments. We expect our results to better equip farmers and environmental practitioners to manage runoff using relatively low-tech bioretention cells with appropriate vegetation and soil amendments.
Project objectives from proposal:
- Quantify the effects of both compost and vegetation on the removal of nutrients and TSS by bioretention cells treating stormwater from a farm production area.
- Measure the change in vertical concentration of nutrients within the bioretention soil media and determine to what extent it is affected by compost and vegetation.