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Physical Sciences and Mathematics Commons™
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Articles 1 - 5 of 5
Full-Text Articles in Physical Sciences and Mathematics
Nutrient Runoff And Leachate After Land-Application Of Digestate In A Laboratory Study Using Rainfall Simulations, Min Xiao
Open Access Theses
There has been an increasing number of anaerobic digesters on livestock farms in the United States during the past two decades. Anaerobic digestion of manure allows production of renewable energy and generation of stabilized and nutrient-rich digestate that can be used as organic fertilizer. However, the majority of the existed studies using liquid digestate as fertilizer only focused on the effectiveness for crop yield, nutrient content and microorganism in soil. There is insufficient understanding in the environmental impact of digestate land-application. This laboratory study used six treatments including four different liquid digestate treatments, a chemical fertilizer treatment, and an unfertilized …
Nitrate Removal From Subsurface Drainage By Denitrifying Bioreactor, Erin Chichlowski
Nitrate Removal From Subsurface Drainage By Denitrifying Bioreactor, Erin Chichlowski
Open Access Theses
Denitrifying bioreactors are an edge-of-field best management practice that reduce nitrate in runoff and subsurface drainage waters with minimum surface foot print and management requirements. The objectives of this study included evaluating a 173 m3 wood chip bioreactor for nitrate reduction and removal rates, the effects on phosphorus, and the impacts of the bioreactor's physical characteristics on effective nitrate reduction During periods of flow, weekly water samples were collected for lab analysis of nitrate+nitrite (nitrate-N), total nitrogen (TN), soluble reactive phosphorus (SRP), and total phosphorus (TP) and measurements were made of water temperature, dissolved oxygen, pH, oxidation reduction potential, temperature, …
Profit-Maximizing Responses To Climate Change In Commodity Agriculture: Does Adaptation Matter?, Sajeev Erangu Purath Mohankumar
Profit-Maximizing Responses To Climate Change In Commodity Agriculture: Does Adaptation Matter?, Sajeev Erangu Purath Mohankumar
Open Access Theses
Accumulation of greenhouse gases in the atmosphere has led to rising temperatures, and is expected to lead to a change in climate. Crop yields are vulnerable to these changes. Adaptation is expected to be key to combating climate change impacts, but the effectiveness of adaptation strategies is not well understood. Hence, there is a need to assess the impacts of climate change on agriculture and devise profitable adaptation strategies to combat its effects. This study uses historical and three projected climate data sets to simulate yields using the crop model Daycent, empirical relationships between weather and agronomic variables that influence …
Assessing Positional Accuracy And Correcting Point Data For Digital Soil Mapping At Varying Scales, Minerva J. Dorantes
Assessing Positional Accuracy And Correcting Point Data For Digital Soil Mapping At Varying Scales, Minerva J. Dorantes
Open Access Theses
Accuracy, timeliness, and the effect of scale of soil maps are rarely assessed. The recent increase in the use of GIS technologies and modelling software in natural resources and land management, has increased the demand for soil information at a finer resolution worldwide. Most of the world's developing countries rely on soils information at a scale that is too coarse for practical planning, and have obstacles impeding collection of new data, such as civil war and a lack of collection resources. The United States has an exhaustive collection of soils data at a fine scale. However, its location information is …
Habitat Restoration Of A Constructed Ohio River Embayment, Caleb Michael Rennaker
Habitat Restoration Of A Constructed Ohio River Embayment, Caleb Michael Rennaker
Open Access Theses
Backwater habitats of large rivers provide habitat for aquatic biota and influence important predator-prey interactions in fishes and other aquatic organisms. However, these areas often exhibit turbid conditions and lack habitat complexity. Restoration of lentic habitats through direct habitat manipulations has shown success in prior efforts, but these methods have not been tested in backwater habitats of large rivers. I attempted to create habitat in an Ohio River embayment by establishing founder colonies of aquatic macrophytes coupled with the placement of underwater gravel beds. I also evaluated the effects of total suspended solids (TSS) on overwintering structures of American Pondweed …