Thesis (Ph. D.)--University of Wisconsin--Madison, 1957. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 248-250).

Thesis (Ph. D. - Economics)--University of Arizona. / Includes bibliographical references.

<p> It is difficult to assess rangeland management practices at a hillslope scale because of the spatial and temporal variability of ecohydrological processes across a landscape. The Conservation Effects Assessment Project (CEAP) aims to provide a cost-effective method for quantifying benefits of conservation practices on rangelands. This study uses the Rangeland Hydrology and Erosion Model (RHEM) to develop a framework to assess rangeland management practices by quantifying sediment yield and runoff. Kaler Ranch, located in Eastern Arizona, was used as a study site because of their recently implemented rangeland conservation practices. Vegetation parameters were developed based on field data collected across the ranch and used to represent various rangeland management scenarios in RHEM. Peak flow and sediment yield rates were determined for each scenario using RHEM and were used as metrics to evaluate rangeland condition. RHEM provided an adequate method to evaluate the relative differences between upland rangeland management scenarios; however, it was less effective at evaluating changes in management practices within a riparian area.</p>

<p> The feed production cost in tilapia diets is driven by the prices of its ingredients such as fishmeal (FM) and soybean meal (SBM). Fishmeal and soymeal combined with other ingredients provides fish with the nutrients required for growth and sustaining life. Soybean meal is used as an alternative to fishmeal, but prices for this traditional ingredient have increased significantly in recent years as a result of high market demand from other industries. Consequently, there has been an increase interest by tilapia nutritionists and feed manufacturers to find less expensive, alternative feedstuffs for use in tilapia diets. </p><p> Camelina <i>(Camelina sativa)</i> is an oil seed crop grown in higher latitudes especially along the US - Canada border, northern China and northern Europe. Camelina after removal of most of the edible oil has been proposed as a fish feed ingredient. </p><p> A sixty-day feeding trial was conducted and diets were formulated to contain various levels of camelina inclusion (0, 5, 10, 15, 20 and 25%) for the &ldquo;camelina meal&rdquo; while the &ldquo;camelina oil&rdquo; was formulated to contain one level (4.7%) of oil and was divided as &ldquo;raw&rdquo; and 4.7 &ldquo;wash&rdquo;. The results indicated that that fishes fed diets containing camelina ingredients had growth performance and feed utilization results that were similar to fish fed the commercial diet (P>0.05). There were significant differences (P&lt;0.05) for body organ indices and body composition. The 15% camelina meal diet was the lowest cost experimental diet per kilogram gain and therefore, this alternative ingredient might be a potential replacement for soymeal in a more cost effective feed formulation. </p><p> The fatty acid composition of tilapia fillets was also analyzed at the end of the feeding trial. The inclusion of camelina meal and oil in tilapia diets resulted in significant increases in the Omega-3/Omega-6 ratio in fillets when compared to the control. The 15% camelina meal provided the best results of the experimental diets yielding significantly higher polyunsaturated fatty acid (PUFA) and lower saturated fatty aid (SFA) than the control diet. </p><p> On a commercial scale, tilapia commercial feeds differ in both formulated nutrient levels and ingredient composition. In intensive system culture, natural food is limited making it important that all nutrients are supplied through a complete pelleted diet. An advantage to feeding a pelleted diet is that the pellet-type feed enables the farmers, feed formulators and manufactures to design a diet that provides an optimal nutritional mix for tilapia. </p><p> Precise levels in the protein and lipid percentages of tilapia diets can reduce feed costs and also reduce the amount of underutilized protein and lipids stored as fat in tilapia. Feed comprises of over 60% of the variable cost in the intensive aquaculture operation; if feed prices were to increase, it would be a substantial amount for tilapia producers to absorb. Therefore an improved diet formulation designed for tilapia can increase profitability. </p><p> Results indicated that the experimental diets (28% Crude Protein (CP)-Amino Acid (AA), 28% CP and 40% CP) performed similar to the control diet (32% CP) as it relates to fish growth. The experiment conducted on a commercial scale at an operating farm found that feeding tilapia the lowest protein level diets (28% CP) resulted in higher biomass gain per raceway, biomass gain per fish and significantly higher protein efficiency ratio (PER) when compared to the control diet (32% CP). The 28% CP diet also had the second best FCR value and most importantly higher returns based on its FCR when compared to the control diet (32% CP).</p>

Orientador: Rodrigo Máximo Sánchez Román / Banca: Antonio Evaldo Klar / Banca: Juan Sinforiano Delgado Rojas / Resumo: Os recursos hídricos têm importância fundamental no desenvolvimento de diversas atividades econômicas. Em relação à produção agrícola, a água pode representar até 90% da constituição física das plantas. A falta d'água em períodos de crescimento dos vegetais pode inviabilizar a produção agrícola e até afetar seriamente ecossistemas equilibrados. Uma das formas de se contabilizar a quantidade de água em determinado sistema é por meio do balanço hídrico, que se constitui de uma importante ferramenta para o processo de avaliação do ciclo da água em uma determinada região ou determinada cultura, visto que representa o somatório das quantidades de água que entram e saem de um dado sistema, em um determinado intervalo de tempo, cujo resultado indica durante o período avaliado se há deficiência ou excedente hídrico para a cultura. Sua importância é indispensável para estudos sobre o regime hídrico, planejamento agrícola, zoneamento agrícola, estudos climáticos, entre outras aplicações. O objetivo central deste trabalho foi determinar o balanço hídrico na sub-bacia hidrográfica do Boi Branco-SP, para servir como ferramenta ao planejamento hidroagrícola e ambiental da região. O balanço hídrico climatológico na escala mensal foi determinado com a finalidade de se conhecer a disponibilidade hídrica da região. Determinou-se também o balanço hídrico de cultivo para o controle de irrigação, nas diversas culturas da sub-bacia com o intuito de verificar os períodos mais críticos de deficiência hídrica no solo, possibilitando um melhor manejo da irrigação. Os dados requeridos para o cálculo do balanço hídrico são os de precipitação, evapotranspiração, dados da cultura instalada e capacidade de armazenamento de água no solo (CAD). ... / Abstract: The water resources are fundamental to the development of several economic activities. Concerning the agriculture production, the water can represent close to 90% of the physical constitution of the plant. The low water supply during the growing stage of vegetables can make the agricultural production not viable and can even seriously affect the balance of the ecosystem. One way to calculate the amount of water in a determined system is by means of the water balance, that is an important tool for the assessment process of the water cycle in a specific region or specific crop, as it represents the sum of water quantity that gets in and out of a given system, in a given time range, whose result indicates - during the assessed period - if there is a shortage or excess of water for the crop. Its importance is essential for the studies on the water regime, agriculture planning, zoning, climate studies, among other uses. The main goal of this work was to establish the water balance in the watershed Boi Branco-SP, so that it can be used as a tool for the hydro-agricultural and environmental planning of the region. The water climate balance in a monthly scale was determined with the aim to recognize the water availability in the region. It was also determined the water balance of tillage for the irrigation control in the different crops of the watershed, aiming to verify the most critical periods of low water supply in the soil, making it possible a better water management. The required data for water balance calculation are the precipitation, evapotranspiration, given by the installed crop and water holding capacity in the soil (WHC). For the water climate balance, it was used data of the historical series of the region, available in pluviometric stations located in the studied area. It was ... / Mestre

Made available in DSpace on 2014-12-02T11:16:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-06-27Bitstream added on 2014-12-02T11:21:36Z : No. of bitstreams: 1 000791546.pdf: 4068550 bytes, checksum: ac1386be409e088ff4e93ed28db59734 (MD5) / Os recursos hídricos têm importância fundamental no desenvolvimento de diversas atividades econômicas. Em relação à produção agrícola, a água pode representar até 90% da constituição física das plantas. A falta d’água em períodos de crescimento dos vegetais pode inviabilizar a produção agrícola e até afetar seriamente ecossistemas equilibrados. Uma das formas de se contabilizar a quantidade de água em determinado sistema é por meio do balanço hídrico, que se constitui de uma importante ferramenta para o processo de avaliação do ciclo da água em uma determinada região ou determinada cultura, visto que representa o somatório das quantidades de água que entram e saem de um dado sistema, em um determinado intervalo de tempo, cujo resultado indica durante o período avaliado se há deficiência ou excedente hídrico para a cultura. Sua importância é indispensável para estudos sobre o regime hídrico, planejamento agrícola, zoneamento agrícola, estudos climáticos, entre outras aplicações. O objetivo central deste trabalho foi determinar o balanço hídrico na sub-bacia hidrográfica do Boi Branco-SP, para servir como ferramenta ao planejamento hidroagrícola e ambiental da região. O balanço hídrico climatológico na escala mensal foi determinado com a finalidade de se conhecer a disponibilidade hídrica da região. Determinou-se também o balanço hídrico de cultivo para o controle de irrigação, nas diversas culturas da sub-bacia com o intuito de verificar os períodos mais críticos de deficiência hídrica no solo, possibilitando um melhor manejo da irrigação. Os dados requeridos para o cálculo do balanço hídrico são os de precipitação, evapotranspiração, dados da cultura instalada e capacidade de armazenamento de água no solo (CAD). ... / The water resources are fundamental to the development of several economic activities. Concerning the agriculture production, the water can represent close to 90% of the physical constitution of the plant. The low water supply during the growing stage of vegetables can make the agricultural production not viable and can even seriously affect the balance of the ecosystem. One way to calculate the amount of water in a determined system is by means of the water balance, that is an important tool for the assessment process of the water cycle in a specific region or specific crop, as it represents the sum of water quantity that gets in and out of a given system, in a given time range, whose result indicates - during the assessed period - if there is a shortage or excess of water for the crop. Its importance is essential for the studies on the water regime, agriculture planning, zoning, climate studies, among other uses. The main goal of this work was to establish the water balance in the watershed Boi Branco-SP, so that it can be used as a tool for the hydro-agricultural and environmental planning of the region. The water climate balance in a monthly scale was determined with the aim to recognize the water availability in the region. It was also determined the water balance of tillage for the irrigation control in the different crops of the watershed, aiming to verify the most critical periods of low water supply in the soil, making it possible a better water management. The required data for water balance calculation are the precipitation, evapotranspiration, given by the installed crop and water holding capacity in the soil (WHC). For the water climate balance, it was used data of the historical series of the region, available in pluviometric stations located in the studied area. It was ...

Orientador: Edson Eiji Matsura / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-07-31T17:22:05Z (GMT). No. of bitstreams: 1 Passerotti_FernandaReiko_M.pdf: 1738775 bytes, checksum: 4f6eacaeda5cea42ebca7f32a2e55bf8 (MD5) Previous issue date: 2000 / Resumo: Estudos anteriores comprovaram que a aplicação da água pelo sistema de irrigação subterrânea é vantajosa para o desenvolvimento das culturas, pois reduz a perda de água por evaporação, melhorando a eficiência de irrigação e diminuindo o aparecimento de doenças, além de economizar água. Em princípio, o sistema deve produzir uma iãixa larga e contínua de umidade, oferecendo uniformidade de aplicação em todo o seu comprimento. Preocupou-se o uso da irrigação subterrânea em condições de campo, controlando a quantidade de água a ser aplicada, avaliando a uniformidade de aplicação na linha de irrigação em função da textura do solo, a probabilidade de entupimento do equipamento e a comprovação da eficiência do equipamento no fornecimento de água. O tubo de irrigação foi testado a duas profundidades e com aplicação em duas e em três linhas de irrigação por canteiro. Procurou-se avaliar qual o tratamento que oferece melhores resultados para parâmetros de sanidade da planta e de desenvolvimento vegetativo e de sistema radicular. Nas medidas de umidade os tratamentos enterrados a 10 em tiveram resultados mais homogêneos, Não foram observadas diferenças significativas entre os tratamentos estudados para matéria seca da parte aérea (MSP A), índice de área foliar (IAF), máxima dimensão horizontal da pJanta (DHP) e altura da planta (AP), tanto em plantas sadias como em plantas doentes. Na avaliação do sistema radicular, apenas alguns tratamentos apresentaram diferença significativa: os tratamentos de raízes sadias e doentes de O a 10 em e de raízes sadias de SO a 60 cm. Na profundidade de O a 10 em, em plantas sadias, no tratamento com 3 linhas a 20 cm, foram observadas medidas menores que os outros três tratamentos. Já as raizes das plantas doentes, de O a 10 cm de profundidade, mostraram valores de peso seco de raiz maiores nos tratamentos de 3 linhas do que nos tratamentos de 2 linhas de irrigação. De SO a 60 cm, as raízes sadias, tiveram resuhados maiores nos tratamentos de 2 linhas do que nos tratamentos de 3 linhas / Abstract: Previous papers have confirmed that applying water througb the subsurface irrigation system is advantageous for the development of cultures, as it reduces the water loss for evaporation, improving irrigation efficacy and diminishing the emergence of diseases. It also promotes water savings. At first, the system should produce a large and continuous humidity string, providing application uniformity in its whole length. We are concemed about the use of subsurfàce irrigation in field conditions, as for controlling the quantity of water to be applied, assessing the application unifonnity on the irrigation string in function of the soil texture, the probability of the equipment clogging, and the confirmation of the equipment efficiency on water supplying. The irrigation pipe was tested at two depths and with application in two and in three irrigation strings per seedbed. The aim was assessing which treatment offers better resu1ts for sanitation parameters of the plant, the vegetative development and the radicular system. As for the humidity measures, the treatments buried at 10 em (3,9 inches) have presented more. It were not observed significant differences among the studied treatments for dry matter of aerial portion, foliar area index, maximum horizontal dimension of the plant and plant height, both in healthy and in sick plants. On the radicular system assessment, only a few treatments have presented significam differences: the treatments of healthy and sick roots at O to 10 cm (3,9 inches) and heahhy roots at 50 to 60 em (19,6 to 23,6 inches). The treatment at O to 10 cm of healthy 3 L 20 cm plants has presented smaller measures than the other three treatments. As for roots of sick plants at O to 10 em of depth, they've shown Jarger results 00 the 3 strings treatment than on the 2 irrigation strings treatments. From 50 to 60 em, the healthy roots have presented larger results on the 2 strings treatments than the 3 strings ones / Mestrado / Agua e Solo / Mestre em Engenharia Agrícola

Agricultural nonpoint source pollution is recognised as a major cause of water pollution. The characteristics of nonpoint source pollution suggest that an efficient approach should focus on a source control and hence land-use management. Recently, the concept of Payments for Ecosystem Services (PES) has been advanced as an efficient market-based approach to protect in-stream water quality, while simultaneously supporting agriculture. Farmers can be rewarded for the adoption of certain ‘Best Management Practices’ (BMPs) in farming systems. But little is known about the adoption of BMPs in the context of Thai agriculture. This thesis examines the adoption of twelve BMPs on citrus farms in the Ping river basin in northern Thailand. In the context of potential PES development, three studies were undertaken using frameworks from economics and psychology. The first study used a bottom-up engineering approach to estimate economic costs of twelve BMPs at the farm-scale. The total annualised costs, including installation, maintenance, and land opportunity costs of each BMP were compared. The results indicated that land opportunity cost was the largest proportion of total costs. These estimates provided a basis for discussion on how the farmers’ perception of cost may influence their stated adoption intention. The second study used the Theory of Planned Behaviour (TPB), to investigate farmers’ intentions on adoption of twelve BMPs. A survey of 218 citrus farmers was undertaken in the application. Descriptive statistics and frequency of BMP selection were presented. The results showed that soil analysis was the most preferred BMP. A graphical analysis of other preferred measures suggested that these were not always consistent with the known cost information derived (above) and thus farmers’ perceived costs might not be the most important factor influencing adoption decisions. Further analysis based on TPB investigated other factors thought to be significant in farmers’ decision-making. Other potential external and psychological factors influencing adoption were investigated using a multinomial logistic model. The results indicated that the probability of adopting BMPs was associated with other psychological factors and external factors, rather than perceived costs. The significant psychological factors were farmers’ attitudes towards consumers and perception about farm returns, while the significant external factors were, for example, access to information and contribution of family labour to farm workload. The third study was based on the application of Q-Methodology, and aimed to obtain a deeper understanding of farmers’ perception towards BMPs. Seventy two participants were purposively selected from the 218 TPB observations. The results revealed four distinctive farmer groups holding different perceptions towards BMPs. The four groups were conservationist, traditionalist, disinterested, and risk-averse. These provided a specific segmentation to guide policy towards influencing attitudes and behaviours. The results suggested that farmers were not motivated solely by a profit maximisation goal. Overall, key findings from these three studies revealed some fundamental requirements for developing a water-related PES programme. These were: i) factors affecting eligibility to participate; ii) factors affecting desire to participate; and iii) factors affecting ability to participate. This information provided the basis for a set of recommendations addressing the development of the water-related PES programme in the Ping river basin.

Orientador: Rodrigo Máximo Sánchez Román / Coorientador: Alba Maria Guadalupe Orellana González / Banca: Célia Regina Zimback / Banca: Leslie Ivana Serino Castro / Resumo: O objetivo do presente trabalho foi formular um modelo para analisar a sustentabilidade hídrica da sub-bacia do córrego do Boi Branco utilizando a metodologia de Dinâmica de Sistemas (DS). A DS é uma ferramenta que permite representar o comportamento de sistemas complexos incluindo as relações de causa e efeito e os enlaces de retroalimentação utilizando um computador para simular modelos matemáticos tornando possível controlar e explorar um sistema real. A sub-bacia do córrego do Boi Branco abrange 80,71 km2 de área de drenagem; sua vertente direita situa-se no sudoeste do município de Paranapanema e a esquerda no sudeste do município de Itaí, entre as Longitudes 48º48'39'' e 48º55'39'' e Latitudes 23º36'01'' e 23º29'00''. Da área total da sub-bacia, 20,09 km2 são irrigados por pivô central e as principais culturas cultivadas são: trigo, algodão, milho, feijão, batata e soja. As simulações para determinar a oferta, a demanda de água e o índice de sustentabilidade foram feitas considerando-se três cenários: Efeitos das precipitações com probabilidade de ocorrência de 75% e 50% em função da eficiência do sistema de irrigação e depois, em função da vazão ecológica de 1/40 e 1/10, para os dois primeiros cenários e para o último cenário, o comportamento da precipitação igual aos 10 primeiros anos da série de 1971 a 1980 na disponibilidade de água e no índice de sustentabilidade para a sub-bacia do Boi Branco. Os resultados evidenciam que a demanda hídrica é maior que a oferta potencial de água superficial, refletindo assim, condições de vulnerabilidade, permitindo ao DAEE classificá-la como crítica de acordo com o artigo 14 da Lei 9.034. Conclui-se que 1) Considerando-se apenas a oferta de água superficial na sub-bacia, e a atividade agrícola irrigada, o recurso hídrico não é sustentável em nenhum dos cenários; 2) a ... / Abstract: This study aimed to formulate a model in order to analyze the water resources sustainability at Boi Branco sub-basin using System Dynamics (SD) methodology. The SD allows to represent the behavior of complex systems including relation between cause and effect, and through feedback linkages mathematical computational simulation models allowing to control and tap a real system. The Boi Branco sub-basin has a drainage area of 80.71 km2; its right arm is located in the southeast city of Paranapanema and its left arm in the southeast city of Itai; between longitudes 48º48'39'' and 48º 55'39'' and latitudes 23º36'01'' and 23º29'00'', respectively. 20.09 km2 of the sub-basin is irrigated by center pivot and, cultivated with wheat, cotton, corn, beans, potatoes and soybeans. Simulations to determine the supply, demand and water sustainability index can be grouped in three scenarios: effects of precipitation with a probability of 75% and 50% and the efficiency of the irrigation system, and considering an ecological flow of 1/40 and 1/10 for the first two scenarios and for the latter scenario, the behavior of rainfall equal to the first 10 years of the series from 1971 to 1980. The results show that water demand is greater than the potential supply of surface water; it reflects vulnerable conditions which classify it as critical, in accordance to Article 14 of Law 9034. It is concluded: 1) Considering only the surface water supply in the sub-basin and irrigated agriculture, water resources are not sustainable in all scenarios; 2) The sustainability of water resources in Boi Branco sub-basin, excluding weather factors will only be possible if farmers include groundwater resources to supplement surface uptake; 3) The efficiency of 4 irrigation systems equal to or greater than 80% reduces water demand; 4) The instream flow 1/40 could be used as a basis for process management, in view of the multiple use ... / Mestre

Made available in DSpace on 2014-12-02T11:16:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-06-13Bitstream added on 2014-12-02T11:21:35Z : No. of bitstreams: 1 000791549.pdf: 2096888 bytes, checksum: ad1314a3c7bab5cfeca0de154e090807 (MD5) / O objetivo do presente trabalho foi formular um modelo para analisar a sustentabilidade hídrica da sub-bacia do córrego do Boi Branco utilizando a metodologia de Dinâmica de Sistemas (DS). A DS é uma ferramenta que permite representar o comportamento de sistemas complexos incluindo as relações de causa e efeito e os enlaces de retroalimentação utilizando um computador para simular modelos matemáticos tornando possível controlar e explorar um sistema real. A sub-bacia do córrego do Boi Branco abrange 80,71 km2 de área de drenagem; sua vertente direita situa-se no sudoeste do município de Paranapanema e a esquerda no sudeste do município de Itaí, entre as Longitudes 48º48’39’’ e 48º55’39’’ e Latitudes 23º36’01’’ e 23º29’00’’. Da área total da sub-bacia, 20,09 km2 são irrigados por pivô central e as principais culturas cultivadas são: trigo, algodão, milho, feijão, batata e soja. As simulações para determinar a oferta, a demanda de água e o índice de sustentabilidade foram feitas considerando-se três cenários: Efeitos das precipitações com probabilidade de ocorrência de 75% e 50% em função da eficiência do sistema de irrigação e depois, em função da vazão ecológica de 1/40 e 1/10, para os dois primeiros cenários e para o último cenário, o comportamento da precipitação igual aos 10 primeiros anos da série de 1971 a 1980 na disponibilidade de água e no índice de sustentabilidade para a sub-bacia do Boi Branco. Os resultados evidenciam que a demanda hídrica é maior que a oferta potencial de água superficial, refletindo assim, condições de vulnerabilidade, permitindo ao DAEE classificá-la como crítica de acordo com o artigo 14 da Lei 9.034. Conclui-se que 1) Considerando-se apenas a oferta de água superficial na sub-bacia, e a atividade agrícola irrigada, o recurso hídrico não é sustentável em nenhum dos cenários; 2) a ... / This study aimed to formulate a model in order to analyze the water resources sustainability at Boi Branco sub-basin using System Dynamics (SD) methodology. The SD allows to represent the behavior of complex systems including relation between cause and effect, and through feedback linkages mathematical computational simulation models allowing to control and tap a real system. The Boi Branco sub-basin has a drainage area of 80.71 km2; its right arm is located in the southeast city of Paranapanema and its left arm in the southeast city of Itai; between longitudes 48º48'39'' and 48º 55'39'' and latitudes 23º36'01'' and 23º29'00'', respectively. 20.09 km2 of the sub-basin is irrigated by center pivot and, cultivated with wheat, cotton, corn, beans, potatoes and soybeans. Simulations to determine the supply, demand and water sustainability index can be grouped in three scenarios: effects of precipitation with a probability of 75% and 50% and the efficiency of the irrigation system, and considering an ecological flow of 1/40 and 1/10 for the first two scenarios and for the latter scenario, the behavior of rainfall equal to the first 10 years of the series from 1971 to 1980. The results show that water demand is greater than the potential supply of surface water; it reflects vulnerable conditions which classify it as critical, in accordance to Article 14 of Law 9034. It is concluded: 1) Considering only the surface water supply in the sub-basin and irrigated agriculture, water resources are not sustainable in all scenarios; 2) The sustainability of water resources in Boi Branco sub-basin, excluding weather factors will only be possible if farmers include groundwater resources to supplement surface uptake; 3) The efficiency of 4 irrigation systems equal to or greater than 80% reduces water demand; 4) The instream flow 1/40 could be used as a basis for process management, in view of the multiple use ...