Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Life Sciences
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 …
Automatic Extraction Of Plots From Geo-Registered Uas Imagery Of Crop Fields With Complex Planting Schemes, Anthony A. Hearst
Automatic Extraction Of Plots From Geo-Registered Uas Imagery Of Crop Fields With Complex Planting Schemes, Anthony A. Hearst
Open Access Theses
Complex planting schemes are common in experimental crop fields and can make it difficult to extract plots of interest from high-resolution imagery of the fields gathered by Unmanned Aircraft Systems (UAS). This prevents UAS imagery from being applied in High-Throughput Precision Phenotyping and other areas of agricultural research. If the imagery is accurately geo-registered, then it may be possible to extract plots from the imagery based on their map coordinates. To test this approach, a UAS was used to acquire visual imagery of 5 ha of soybean fields containing 6.0 m2 plots in a complex planting scheme. Sixteen artificial targets …
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 …