| A comparison of water flow and nitrogen flux to groundwater under conventional till (CT), a Best Management Practice (BMP) and a grass plot is presented. The research was performed to help explain the impact of management practice on potential losses of contaminants from agricultural soils. Hydraulic head and nitrate-N concentrations were monitored in order to determine fluxes moving beneath the agricultural fields. Findings from the study were that nitrate-N concentrations in both the unsaturated and saturated zones were variable with depth, although, concentrations decreased with time under all management schemes. Also, no significant differences in nitrate-N fluxes were calculated between CT and BMP plots in the unsaturated zone, but in the saturated zone, higher fluxes of nitrate-N were seen under CT management than under the BMP plot. Simulating the BMP plot with Hydrus-2D showed that the model overestimated the influence of the tile drain, but based on the relatively small amount of available information, Hydrus-2D performed satisfactorily simulating hydraulic head data that reasonably depicted the field measured data.*; *This dissertation is compound (contains both a paper copy and a CD as part of the dissertation). The CD requires the following system requirements: Microsoft Office. |
