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Sustainable Fertilizer Management Practices For Container Nursery Production, Saroj Burlakoti

All Graduate Theses and Dissertations, Fall 2023 to Present

Growing nursery plants in containers requires a timely supply of mineral nutrients for optimum growth. However, there is a misconception among growers that the application of higher doses of fertilizers hastens plant growth; instead, it can lead to runoff and leaching loss of nutrients. Reducing fertilizer application while sustaining healthy plants can not only negate environmental consequences but also save fertilizer costs. For example, two ground covers, Lysimachia nummularia (creeping jenny, moneywort) and Vinca minor 'Bowles' (periwinkle), can be grown for three months by applying 6 mg/L of phosphorus (P) as reduction of P to single application of 6 mg/L …

Exploring Cation Exchange: Unveiling Its Significance In Biochar And Bioenergetics Applications, Gyanendra Kharel

Chemistry & Biochemistry Theses & Dissertations

Cation exchange, a cornerstone of soil chemistry and nutrient cycling, is a fundamental chemical process that occurs in soils, sediments, membranes, and other solid materials. It involves the interchange of positively charged ions, or cations, between a solid matrix and a surrounding solution. This process is crucial in various natural and engineered systems, leading to a range of applications across different fields.

This dissertation presents an extensive investigation into the applications of cation exchange in the fields of biochar and bioenergetics, encompassing three distinct aims. The first aim concentrates on the surface oxygenation of biochar through ozonization, aiming to achieve …

Comparing Phosphorus Removal Efficiencies And Mechanisms Via Two Cost-Effective Specialty Adsorbents In A Cascade Upflow Filtration System, Sydney Kilgus-Vesely

Honors Undergraduate Theses

Finding solutions to treat water that contains phosphorus is an important effort due to the harmful impacts it presents to both human health and the environment. Phosphorus is considered a limiting factor in water oftentimes and therefore controls the growth of algal bloom in a water body. The increase of algal populations due to wastewater effluent, stormwater runoff, and agricultural discharge in Florida waters has a direct link to the event of harmful algal blooms such as red tide in coastal regions, eutrophication of waterbodies, and fish kills. Finding low cost, energy efficient, and low maintenance green sorption media (GSM) …

Upcycling Dairy Manure Fine Solids Captured By Dissolved Air Flotation As Part Of A Phosphorus Recovery And Reuse Strategy, Katherine Keith Porterfield

Graduate College Dissertations and Theses

Dissolved air flotation (DAF) has shown potential to substantially improve phosphorus (P) mass balance on dairy farms by capturing P associated with fine solids from liquid manure, enabling new management options. However, at < 25% total solids, further dewatering and other upcycling is necessary to facilitate export of recovered fine solids off farm for use in bagged or bulk products. I generated plant foods using DAF-captured dairy manure fine solids thermally dried to 45% total solids blended with other organic residuals. Dry biomass of tomato and marigold seedlings amended with 6% v/v plant food was six-times greater than the unamended control and not significantly different from a market alternative treatment. Because thermal dewatering can be prohibitively costly, I generated a second batch of plant foods using DAF-captured dairy manure fine solids conditioned with 3, 4.5 and 6% (w/w) quicklime or lime kiln dust (LKD) and dewatered using a benchtop press for comparison with thermally dried fine solids. Tomato seedling biomass was similar for thermally dried and LKD plant foods, but quicklime plant foods had no effect compared to the unamended control. Quicklime and LKD conditioned fine solids contained approximately 30 and 10 times less plant-available P than thermally dried fine solids, respectively—likely due to precipitation of Ca-P minerals. These studies indicate that DAF-captured dairy manure fine solids could be upcycled to bagged horticultural products with substantial agronomic value, however sustainable materials drying remains a key challenge to realizing this potential.

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. …

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 …

The Effects Of Biochar Age And Concentration On Soil Retention Of Phosphorus And Infiltration Rate, Emilie Schneider

Natural Resources Management and Environmental Sciences

Changes in land use and land management practices are regarded as one of the main factors in altering the hydrogeological system, causing changes in runoff, surface supply yields, and the quality of receiving water (Tong and Chen, 2002). Phosphorus is a significant contributor to accelerated eutrophication of fresh water and is largely sourced from agricultural runoff (Sharpley et al., 1994). The dominant processes controlling solution composition in agricultural soils are primarily ‘chemical’ for P (i.e. adsorption/desorption and dissolution/precipitation) (Edwards and Withers, 1998). Biochar has chemical characteristics that have the potential to adsorb P or influence precipitation of P insoluble pools …