The monitoring of nitrate mass load through the unsaturated zone below agricultural land was proposed as a novel technique to assess the effect of agricultural best management practices (BMPs). The objectives of the study were to: develop field techniques and apply computational models for the quantification of unsaturated zone nitrate mass flux; scale the point mass flux results to a nitrate mass load across an agricultural parcel; and assess the resulting nitrate mass load measurements as indicators to evaluate the effect of a BMP. At several locations across the study site, groundwater quality and profiles of soil water content and temperature were regularly monitored, and several rounds of geologic cores were collected for analysis of bulk soil nitrate and an applied bromide tracer. The field data were applied in several analytical techniques for estimating recharge, and in two unsaturated zone numerical models used to refine the recharge estimates. The recharge rate at each measurement location was then combined with unsaturated zone nitrate data to quantify nitrate mass flux. Upscaling of the flux values to field-scale mass load was based mainly on topography, geology and field observations. The calculation of stored nitrate mass in the shallow subsurface showed some correlation to changes in surface nitrogen application, with the greatest decreases in stored mass observed at locations underlain by sand where there was a switch to a grass crop. In contrast, the calculation of nitrate mass load suggested that the post-BMP value (4.1 t NO3-N/yr) was greater than the pre-BMP value (2.2 t NO3-N/yr). However, the calculation of nitrate mass load was limited by several factors, including a lack of nitrate concentration data from the deep unsaturated zone and an above-average annual precipitation rate; as a result, the findings suggesting an increase in nitrate mass load in response to decreasing nutrient inputs should be interpreted with caution. Continued monitoring of nitrate mass load and stored nitrate mass in the unsaturated zone is recommended to determine whether further benefits from the BMPs are observed as the measurement period lengthens and the unsaturated zone is progressively flushed.

The monitoring of nitrate mass load through the unsaturated zone below agricultural land was proposed as a novel technique to assess the effect of agricultural best management practices (BMPs). The objectives of the study were to: develop field techniques and apply computational models for the quantification of unsaturated zone nitrate mass flux; scale the point mass flux results to a nitrate mass load across an agricultural parcel; and assess the resulting nitrate mass load measurements as indicators to evaluate the effect of a BMP. At several locations across the study site, groundwater quality and profiles of soil water content and temperature were regularly monitored, and several rounds of geologic cores were collected for analysis of bulk soil nitrate and an applied bromide tracer. The field data were applied in several analytical techniques for estimating recharge, and in two unsaturated zone numerical models used to refine the recharge estimates. The recharge rate at each measurement location was then combined with unsaturated zone nitrate data to quantify nitrate mass flux. Upscaling of the flux values to field-scale mass load was based mainly on topography, geology and field observations. The calculation of stored nitrate mass in the shallow subsurface showed some correlation to changes in surface nitrogen application, with the greatest decreases in stored mass observed at locations underlain by sand where there was a switch to a grass crop. In contrast, the calculation of nitrate mass load suggested that the post-BMP value (4.1 t NO3-N/yr) was greater than the pre-BMP value (2.2 t NO3-N/yr). However, the calculation of nitrate mass load was limited by several factors, including a lack of nitrate concentration data from the deep unsaturated zone and an above-average annual precipitation rate; as a result, the findings suggesting an increase in nitrate mass load in response to decreasing nutrient inputs should be interpreted with caution. Continued monitoring of nitrate mass load and stored nitrate mass in the unsaturated zone is recommended to determine whether further benefits from the BMPs are observed as the measurement period lengthens and the unsaturated zone is progressively flushed.

Eutrophic conditions caused Severn Sound to be listed as an Area of Concern in the 1980’s, it was then delisted in 2002 after implementing a number of agricultural Best Management Practices (BMPs). The focus of this research is to evaluate BMP effectiveness on a watershed scale using both monitoring and modelling. The monitoring data clearly shows that the BMPs significantly reduced the sediment loadings. It also showed that BMPs affect only the intercept and not the slope of the sediment rating curves meaning that BMPs reduce sediment loadings in a linear fashion and at a constant percentage for all sizes of storms. The literature review and associated BMP reduction factors used to model the applied BMPs clearly show that observed and predicted reductions in sediment were experienced and that the model is validated for use on a watershed scale for BMP implementation. The results from this research will further the understanding of how sediment transport curves are affected by Best Management Practices. / Chapter 1 defines the problem and scope of the research study to be examined in this thesis. The literature review presents the current state of knowledge related to the effectiveness of BMPs, sampling techniques, and the use of sediment transport curves, and watershed modelling as a tool to evaluate the use of BMPs. Chapter 3 explains the goals and objectives as well as the study area for this research. Outlined in Chapter 4 are the standard methods used for water quality monitoring and setting-up and calibrating a watershed model. Research results are presented in Chapter 5 and include measured streamflow and water quality results for the respective rivers along with results from watershed modelling. The results section also reflects on the implications for BMP effectiveness and areas of future research. Chapter 6 concludes with a summary of the new information gained from this research and the success of Severn Sound in leading the way in improved use of BMPs for a healthier watershed. / Severn Sound Environmental Association, Greenland International Consulting Ltd., University of Guelph School of Engineering

Dramatically higher fuel prices and massive petroleum imports from politically unstable countries have contributed to a major national initiative to generate renewable fuels in the United States. Often, such policies are enacted and implemented with huge taxpayer expenditures without due diligence to the consequences. The evaluation of the water quality impacts of converting pastureland to intensive biomass production for fuel in a southern Texas watershed suggest significant increases erosion and nutrient loadings to water bodies. The Best Management Practices (BMPs), cover crop and filter strips when implemented individually failed to produce status-quo reduction levels. Combined BMPs implementation produced improved mitigation, at substantially higher costs, highlighting the issue of sustainability related to the economics of renewable fuels. The estimation of the net energy of biomass ethanol accounting for the production input data indicate a greater than one energy return for biomass crops. However, the policy results indicate that only 70 percent in net contribution to the energy supply is achieved due to relatively lower energy returns compared to conventional fossil fuels. In addition, because the ethanol produced has to have the energy used deleted from the total, the cost of producing a gallon of biomass ethanol is substantially higher than that of gasoline. The impacts of an exogenously-specified biofuel mandate fulfilled by the production of a dedicated biomass crop and its consequent effects on commodity prices and overall welfare are estimated. Net farm income increased due to an increase in crop prices; however, both consumer surplus and total surplus decreased. The analysis is extended to estimate the sensitivity of Conservation Reserve Program (CRP) acres returning to crop production and the potential of higher biomass yields. The results indicate that net farm income decreased and consumer surplus increased due to a decrease in crop prices, resulting in an increase in overall welfare. This current research evaluates the unintended consequences of the U.S. energy policy and provides interesting insights of the potential economic and environmental impacts. These results suggest policy makers should be cautious before enacting energy policy and consider multiple alternative energy sources in an economic and financial context to achieve a sustainable energy goal.

Thesis (M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (ℓ. 111-121)

Thesis (M.S.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains ix, 109 p. : ill. (some col.), maps (part col.). Includes abstract. Includes bibliographical references (p. 103-105).

Thesis (M.S.) University of Missouri-Columbia, 2004. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (June 29, 2006) Vita. Includes bibliographical references.

Thesis (M.S.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 21, 2007) Includes bibliographical references.

Thesis (M.S.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 27, 2007) Includes bibliographical references.

O objetivo deste trabalho foi de avaliar economicamente uma unidade de produção de alevinos de espécies reofílicas do estado de Rondônia e desta forma estruturar a análise de custos, econômica e gerencial do empreendimento. O empreendimento avaliado possui 54 ha de área total e 6,5 ha de lâmina d’água disponíveis para a alevinagem. Na safra 2010/2011 o empreendimento produziu os seguintes produtos: alevinos de tambaqui (Colossoma macropomum) nos tamanhos de 3g, 5g, 10g, 15g, 20g e 30g; alevinos de piavuçu (Leporinus macrocephalus); e alevinos de curimba (Prochilodus lineatus). O empreendimento ainda comprou e revendeu alevinos de pirarucu (Arapaima gigas) e alevinos de Jundiara (♀ Pseudoplathystoma fasciatum X ♂ Leiarius marmoratus). A fim de avaliar como a produção de alevinos consumiu os recursos disponíveis do empreendimento, realizou-se o mapeamento do fluxo de produção do empreendimento e de sua estrutura que custos . Foram calculados os seguintes indicadores de custo e rentabilidade: custo operacional efetivo e total, custo total de produção, receita liquida e lucro, além dos indicadores de fluxo de caixa usuais e seus alternativos integrados, ponto de nivelamento e margem de contribuição total. Através do mapeamento do fluxo de produção verificou-se que o plantel de reprodutores apresenta resultados reprodutivos satisfatórios, porém o empreendimento apresenta falhas no manejo de arraçoamento de reprodutores e alevinos e não realiza o controle dos estoques de alevinos e dos parâmetros de qualidade de água nos viveiros. Entre os produtos efetivamente produzidos no empreendimento, os que apresentaram os menores custos médios e as melhores rentabilidades estão os alevinos de tambaqui de 3g, 5g e os alevinos de piavuçu. A análise custos e econômica mostrou que empreendimento apresenta uma baixa lucratividade a médio prazo em relação ao capital investido e economicamente inviável a longo prazo, devido a sua onerosa estrutura de produção. Diante destes resultados fica evidente que as tomadas de decisão para determinação de valores de investimento e preço de venda dos produtos são realizadas sem todas as informações necessárias para o adequado planejamento do empreendimento, o que mostra a importância do contínuo controle dos processos e avaliação econômica deste tipo de empreendimento. / The objective of this study was to evaluate a unit cost of production of fingerlings of reophilic species in the state of Rondônia, Brazil, and thereby structure the cost analysis, and the economic management of the enterprise. The enterprise has 54 ha and 6.5 ha of water is available for the nursery. In the season 2010/2011 the enterprise produced the following products: fingerlings of tambaqui (Colossoma macropomum) in 3g, 5g, 10g, 15g, 20g and 30g weights; piavuçu fingerlings (Leporinus macrocephalus) and curimba fingerlings (Prochilodus lineatus). The venture has bought and resold pirarucu fingerlings (Arapaima gigas) and jundiara fingerlings (♀ Pseudoplathystoma fasciatum X ♂ Leiarius marmoratus). In order to evaluate how the production of fingerlings consumed the resources of the enterprise, was conducted the flow map of production of the enterprise and its cost structure. Was calculated the following indicators of cost and profitability, and total operational cost, total cost of production, net income and earnings, and indicators of cash flow and its usual alternative integrated point of leveling and total contribution margin. By mapping the production flow it was found that the bloodstock breeding presents satisfactory results, but the venture fails in the management and feeding of fingerlings and does not perform the control of fingerlings stocks and the parameters of water quality. Among the products actually produced in the enterprise, who had the lowest average costs and better returns are 3 g and 5 g tambaqui fingerlings, and piavuçu fingerlings. The analysis showed that costs and economic analysis has low profitability in the medium term in relation to capital invested and economically unviable in the long term, due to its costly production structure. Given these results it is evident that the decision making process for determining values of investment and the selling price of the products are made without all the information necessary for proper planning of the enterprise, which shows the importance of continuous control process and economic evaluation of this type of business venture.