Physical Sciences and Mathematics Commons^™

Investigating Spatial And Temporal Variability Of Environmental And Biological Controls On Riparian Soil Denitrification, Brittany Victoria Lancellotti

Graduate College Dissertations and Theses

Soil denitrification is a critical component of nitrogen (N) cycling on Earth. It is a microbially-mediated process that removes N from soils by reducing nitrate (NO3-), a highly bioavailable molecule and significant contributor to eutrophication, to gaseous forms of N (N2 or N2O). Riparian areas, which are located at the interface between terrestrial and aquatic ecosystems, are areas of elevated denitrification rates, as they frequently exhibit favorable conditions for this process. Denitrification provides a critical ecosystem service by reducing N inputs to streams and rivers. However, this process is highly variable in time and space, making it difficult to predict …

Phosphorus And Nitrogen Losses In Runoff From Fields With And Without Tile Drainage, Leanna Thalmann

Graduate College Dissertations and Theses

Nutrient losses in surface and subsurface drainage from crop fields have important water quality implications. The deterioration of water quality in segments of Lake Champlain has led to efforts to reduce phosphorus (P) and nitrogen (N) export from agricultural fields. This thesis presents data from two years of edge-of-field monitoring in two adjacent corn (Zea mays L.) silage fields in Keeseville, New York. One field has only surface drainage improvements with monitoring equipment, and the other has both surface and subsurface drainage modifications and monitoring equipment. The study took place from October 2018 to September 2020 and quantified flow and …

Evaluation Of Nitrogen And Phosphorus Removal In Alternative Management Practices For Dairy Farm Production Area Runoff: Bioretention Cells And A Woodchip Bioreactor Treatment System, Jillian Sarazen

Graduate College Dissertations and Theses

Non-point source pollution from agricultural areas can lead to the degradation of downstream water bodies, including eutrophication and harmful algal blooms, due to high concentrations of nitrogen (N) and phosphorus (P) emanating from these areas. One source of agricultural runoff that is often overlooked, originates from agricultural production areas, which have impervious surfaces, such as paved and compacted areas, barnyards, cow paths, and silage bunker storage; these areas generate stormwater runoff and contribute to pollution during storm events.

This research evaluates two built stormwater runoff treatment systems designed to treat high concentrations of nutrients in runoff from a dairy farm. …

The Environmental Microbiome In A Changing World: Microbial Processes And Biogeochemistry, Stephanie Juice

Graduate College Dissertations and Theses

Climate change can alter ecosystem processes and organismal phenology through both long-term, gradual changes and alteration of disturbance regimes. Because microbes mediate decomposition, and therefore the initial stages of nutrient cycling, soil biogeochemical responses to climate change will be driven by microbial responses to changes in temperature, precipitation, and pulsed climatic events. Improving projections of soil ecological and biogeochemical responses to climate change effects therefore requires greater knowledge of microbial contributions to decomposition. This dissertation examines soil microbial and biogeochemical responses to the long-term and punctuated effects of climate change, as well as improvement to decomposition models following addition of …

Nutrient Removal Performance Of A Wood Chip Bioreactor Treatment System Receiving Silage Bunker Runoff, Deborah Joy Kraft

Graduate College Dissertations and Theses

Silage bunker runoff is a form of agricultural pollution that contributes to aquatic ecosystem degradation. Current handling and treatment methods for this process wastewater are often ineffective or expensive. A woodchip bioreactor is an emerging treatment technology designed to facilitate denitrification through the provision of an anaerobic, carbon rich environment. A wood chip bioreactor treatment system, consisting of three pre-treatment tanks, two wood chip bioreactors, and one infiltration basin, was constructed at the Miller Research Complex in South Burlington, Vermont in 2016. Runoff and leachate from an adjacent silage storage bunker is directed into the system. The pre-treatment tanks include …