Dissertations / Theses on the topic 'Agriculture Linear programming'

Although these is considerable uncertainty in the literature about the effects of greenhouse gases on the climate there is little doubt that the composition of the atmosphere has changed in recent times. As a result of human activities the concentration of CO₂ is likely to double from pre-industrial levels by the middle of next century and as a consequence, global temperatures are likely to rise. The potential importance of a change in the climate for the environment and agriculture and the complexity of the issues that are involved means that it is important to develop analytical tools to study this problem. The principal aim of the study is to evaluate the possible effects of a change in climate on the pattern, structure and viability of agriculture in Scotland. To address this objective it was necessary to evaluate the effects of climate change at a range of different levels of resolution. A linear programming model was developed that includes a large amount of biological, physical and economic detail. The models of crop growth (grass, grass/clover, swedes, potatoes, barley, vining peas, oilseed rape and wheat) account for variations in weather conditions, soil types, weeds, applications of nitrogen and pesticides, different planting dates and cropping rotations. The livestock operations that are modelled include sheep, dairy and beef fattening enterprises. In addition a considerable amount of effort was devoted to modelling variations in machinery requirements (and the sensitivity of these operations to climate) labour, buildings and finance. The inclusion of this information has allowed the types of adjustments that farmers may implement to be considered. The model is structured as a series of linked sub-problems where the most basic units are farms. In turn the interactions between farmers in terms of flows of intermediate goods, land and labour are considered at the regional and national level. While further developments to the model would allow the status of Scottish agriculture to be more accurately modelled the model in its current stage of development has allowed a realistic evaluation of the effects of climate change to be performed. The results of this study suggest that climate change will have a detrimental effect on Scottish agriculture, however, the effects of climate are likely to vary between the different farm types and regions. In general, cropping farms are likely to benefit from a change while the profitability of livestock farms, and sheep farms in particular, will decline.

Agriculture in Cape Verde is severely constrained by a harsh physical environment, and large amounts of foreign aid are required to meet demand for food. Policy-makers believe that the development of irrigated farming offers the most potential for increasing food production, requiring a transition from the dominant irrigated crop, sugar cane, to food crops. Linear programming techniques are used to model a representative farm on the island of Santiago. Water constraints are varied parametrically, showing that revenues are extremely sensitive to frequency of irrigation, and that the dominance of low-profit crops is explained by unreliable and long watering intervals. The shift from cane to more profitable food crops will therefore require water reform aimed at increasing irrigation frequency and improving its reliability. Significant improvements in food production and farm incomes can be achieved even considering present supplies of water and land.

A Agricultura Orgânica oferece, ao mercado consumidor, produtos isentos de agentes químicos. Os produtores que fazem uso do sistema convencional e estiverem interessados em adotar a tecnologia orgânica de produção deverão se credenciar junto ao Ministério da Agricultura através de uma certificadora de produtos orgânicos. A certificação pode ser por auditoria ou participativa, mas para recebê-la o agropecuarista deve seguir as normas e procedimentos estabelecidos pela legislação brasileira de produtos orgânicos. Um dos procedimentos é o processo de conversão ou transição, pelo qual a atividade agrícola em manejo convencional muda para o manejo orgânico. O tempo de transição pode variar de 12 a 18 meses, no mínimo, de acordo com a espécie vegetal ou animal e pelo histórico da unidade produtiva. No caso do café, a conversão do sistema convencional para o orgânico pode trazer consigo, entre outros benefícios, a independência de insumos externos, menor risco para a saúde e pode proporcionar maior lucro ao produtor. Esta pesquisa tem como objetivo desenvolver um planejamento de produção do café para o processo de conversão da técnica convencional para a orgânica no Sítio Terra Verde em Espírito Santo do Pinhal no estado de São Paulo. Utilizou-se a metodologia de programação linear para maximizar o lucro e minimizar o custo de produção do café em seis cenários. O plano de conversão foi de oito anos, respeitando a bienalidade do cafeeiro, passando por três fases de manejo: substituição de insumos, conversão e produção orgânica. Foram realizadas três análises sobre o planejamento de conversão. Os resultados da primeira análise mostraram que a adoção da técnica orgânica proporcionou ao cafeicultor lucros superiores aos do sistema convencional no final do período de conversão, quando ocorre aumento sobre o preço da saca. Os cenários da segunda análise identificaram uma situação de prejuízo ao cafeicultor no 4º ano do planejamento e uma condição econômica desvantajosa em relação ao sistema convencional, pois o lucro geral foi inferior, devido à redução da produtividade até o final da conversão. A terceira análise apresentou uma situação em que o produtor não recebe o incremento sobre o preço da saca de café quando em manejo orgânico, o que levou à obtenção de resultado desvantajoso ao produtor, no qual o lucro geral do sistema orgânico foi muito baixo em relação ao do sistema convencional. Conclui-se que especificamente para o Sítio Terra Verde, pode ser economicamente viável a adoção da produção orgânica na cultura do café, mas é com extrema dependência do diferencial do preço entre os sistemas convencional e orgânico.
Organic agriculture offers products to the consumer market free of chemicals. Producers who use the conventional system and are interested in adopting organic production technology must be certified by the Ministry of Agriculture through a certification of organic products. Certification may be obtained by auditing or participatory, but in order to receive it, the rural producers must follow the rules and procedures established by the Brazilian laws for organic products. One example is the process of conversion or transition, through which the agricultural activity is converted from conventional farming to the organic one. The transition time may vary from 12 to 18 months, at least, according to the vegetal or animal species and the farm history. In the case of coffee, the conversion from conventional to the organic system can bring some benefits, for example, the independence of external inputs, risk lower to health and can provide more profit to the producer. Thus, this research aims carry out a coffee a plan of partial conversion to organic production technology for a rural property called Sítio Terra Verde at Espírito Santo do Pinhal, São Paulo State, which uses the conventional system. It was used linear programming to maximize profit and minimize costs of coffee production in six scenarios. The conversion planning was established to occur in eight years, respecting the twice yearly harvesting, with three stages: input substitution, conversion and organic production. Were held three analysis on the conversion plan. The results of the first analysis showed that the adoption of organic technique provided greater profits for the producers than the conventional system at the end of the conversion period, when the coffee bag\'s price raises. The second analysis scenarios identified a prejudice situation for the producer in the 4th year of planning and a disadvantage economic condition compared to the conventional system, because the overall profit was lower due to the reduction in productivity by the end of conversion time. The third analysis showed a situation where the producer does not receive a higher price due to the organic management, with a disadvantageous result for the producer, since the overall profit of the organic system was much lower compared to the conventional system. It was concluded that specifically for Sítio Terra Verde the adoption of organic management for the coffee farming can be economically viable, but it is extremely dependent on price differential between conventional and organic systems.

Nutritional and Economic Analysis of Small-Scale Agriculture in Imbabura, Ecuador Intervention projects in the developing world normally aim to satisfy either the nutritional needs of a group, or advancing the economic stability, but not both. One of the many issues that may arise by narrowly focusing and creating an aid program is that although a group may be fed, they are not equipped to mitigate risks that will arise after project completion and thus continue or revert back to a malnourished state. A bridge is required to join the economic and nutritional programs to create aid interventions that are sustainable past the point of donor separation. This paper proposes the creation of a linear program model to assess the effectiveness and sustainability of such intervention programs. Investigating the effects of merging economic and nutrition interventions as pursued in this report required the first step to be the creation of economic information for a typical small-scale farm. The region of Cochas, Imbabura, Ecuador was selected as the study area in which data would be collected for a representative sample of production and living circumstances of a poor, rural, and small-scale farmer. A comprehensive set of estimated cost and return (enterprise) budgets for small-scale agricultural crops that could be grown by the representative farm family used in this analysis was developed. This was accomplished via data collected in rural Ecuador by Jake Erickson, a Master's student in the department of Applied Economics at Utah State University. Of the supervisory committee, daily interaction occurred with Dr. DeeVon Bailey, project supervisor, and Dr. Ruby Ward, linear program specialist, whom were crucial in project completion. Various scenarios of the linear program were run with variations to the selection of nutritional requirements, off-farm income, and allowing food purchases off the family farm. Each of these scenarios was pursued as they mimic circumstances in which families may struggle to exist within the developing world. The results of each run are compared across the set of results to help understand what assumptions need to exist to validate an intervention's approach to improving the standard of living or nutrition of the world's poor, rural, small-scale farmers. This model is a preliminary attempt at assessing the sustainability of merging common intervention approaches and it should be recognized that further development is needed to create a more encompassing model. Utilizing enterprise budgets, a linear programming model, and nutritional information, such as is done in this study, can help in planning rural development interventions as the income maximization and least-cost diet models are integrated into one within the resource and management constraints of the representative small-scale farm.

A agricultura em Timor-Leste é de natureza familiar e um modo de vida para as populações rurais que são a maior parte da população. O objectivo deste trabalho é medir o bem-estar dos agregados familiares tendo como principal indicador o rendimento disponível, com base em actividades produtivas, reprodutivas e comunitárias, as quais são centrais à organização e funcionamento das comunidades rurais timorenses. A metodologia utilizada para representar o funcionamento dos agregados familiares é a programação linear etnográfica (PLE), o que representa do ponto de vista científico um contributo importante na investigação dos sistemas de agricultura familiar e do bem-estar dos produtores em Timor Leste. A PLE permite testar políticas, tecnologias, alterações reprodutivas e mudanças das normas sociais comunitárias, explorar os respectivos resultados e prever as consequências para o futuro dos agregados familiares e das comunidades rurais. Os resultados mostram que os agregados familiares com explorações agrícolas de pequena e, nalguns casos também as de média dimensão, nas condições actuais, não geram rendimento suficiente para níveis de consumo e bem-estar acima da linha da pobreza. As alternativas de política de transferência tecnológica, assim como o excedente da mão-de-obra masculina em trabalho fora da exploração, são insuficientes para guindar as explorações de pequena dimensão a ultrapassar a linha da pobreza. Outras alternativas, como o apoio directo ao rendimento são possíveis, mas dependem dos recursos disponíveis para a sua implementação enquanto, a médio e longo prazo, o aumento da área das explorações, afigura-se uma opção mais válida para quebrar o ciclo vicioso da pobreza. Mas esta última alternativa, requer uma formulação de política fundiária que tenha em conta todas especificidades socio-étnico-culturais dos agregados rurais timorenses; ABSTRACT: Agriculture in Timor-Leste is family-based and a way of life for the rural population who are the majority of the population. The objective of this work is to measure the well-being using as main indicator the disposable income, taking into account not only productive activities but also reproductive and community activities, which are central to the organization and functioning of East Timorese rural communities. The methodology used to represent the functioning of households is linear ethnographic programming (PLE), which represents from the scientific point of view an important contribution in the investigation of family farming systems and the welfare of producers in East Timor. The PLE models allow us to test policies, technologies, reproductive changes and changes in community social norms, explore their results and predict the consequences for the future of households and rural communities. The results show that households with small farms, and in some cases also medium-sized ones, under current conditions do not generate sufficient income for levels of consumption and well-being above the poverty line. Technological transfer policy alternative, as well as off-farm work of the male labor surplus, are insufficient to drive small farms beyond the poverty line. Other alternatives, such as direct income support, are possible but depend on the resources available for their implementation, while in the medium and long term the increase in holdings area is a more valid option to break the vicious cycle of poverty. But the latter alternative requires a land policy formulation that takes into account all socio-ethniccultural specificities of Timor-Leste rural households.

O aumento da pressão sobre os recursos hídricos tem levado muitos países a reconsiderarem os mecanismos utilizados na indução do uso eficiente da água. Isso é especialmente verdade para a agricultura irrigada, uma das principais consumidoras de água. Estabelecer o preço correcto da água é um dos mecanismos de tornar mais eficiente a alocação da água. Contudo, a definição de um preço para a água é ainda uma tarefa controvérsia principalmente nos países em que as populações rurais têm rendimentos deficientes. Assim, o presente trabalho de dissertação tem como objectivo a análise dos impactes económicos, sociais e ambientais de políticas de preço da água. A metodologia utilizada foi a Programação Linear, fazendo a sua aplicação ao Perímetro Irrigado do Vale de Caxito, localizado na Província do Bengo, a 45 km de Luanda, que tem como fonte o rio Dande; ABSTRACT:Increased pressure on water resources has led many countries to reconsider the mechanisms used in the induction of efficient water use. This is especially true for irrigated agriculture, a major consumer of water. Establishing the correct price of water is one of the mechanisms for more efficient allocation of water. However, the definition of a price for water is still a controversial task especially in countries where rural populations have poor yields. Thus, this dissertation aims to analyze the economic, social and environmental impacts of water price policies. The methodology used is the linear programming, making its application to the Irrigated Valley Caxito, located in Bengo Province, 45 kilometers from Luanda, which has as its source the river Dande.

L’agriculture française est soumise à de fortes pressions. Elle subit une injonction forte à évoluer vers l’agroécologie, à adopter les principes de la production intégrée, à réduire l’usage de pesticides. Dans ces conditions, une transition vers des systèmes agricoles plus respectueux de l’environnement ne doit pas dégrader la compétitivité des exploitations et le revenu des agriculteurs.Le travail présenté ici a pour ambition de contribuer à la réflexion sur les possibilités de changer les modèles d’agriculture. L’objectif est d’évaluer les conséquences économiques et environnementales d’une adoption généralisée des principes de protection intégrée sur une région agricole en fonction de la diversité des situations de production. La Région Bourgogne est retenue dans le cadre de ce travail. Elle dispose de ressources expérimentales en production intégrée grâce à l’investissement historique de la recherche, du développement et de l’enseignement agricole dans cette région. Par ailleurs, la Bourgogne présente un bon compromis entre la diversité de ses situations de production en grandes cultures et le nombre de situations contrastées à considérer pour rendre compte de l’ensemble du territoire. Dans un premier temps, nous avons caractérisé la diversité des situations de production de la Bourgogne et la diversité des systèmes de culture, et nous avons étudié comment les systèmes de culture sont déterminés par les situations de production. Puis nous avons mis en place une méthode pour générer des systèmes de culture optimisés sur le plan économique dans le cadre des contraintes locales et des principes de protection intégrée. Cette méthode mobilise la programmation linéaire sous contrainte, mise en œuvre avec le logiciel GAMS. Elle a été testée pour deux situations de production contrastées de la Bourgogne, correspondant aux zones de plaines sans élevage et aux plateaux argilo-calcaires superficiels. Nous avons évalué les systèmes de culture simulés pour un ensemble de critères de la durabilité économique, sociale et environnementale. Nous les avons comparés aux performances des systèmes actuels dans ces milieux.Les résultats confirment que les systèmes de culture optimisés avec les principes de la protection intégrée sont différents en fonction du contexte de production. La performance économique est plutôt améliorée par rapport aux systèmes actuels dans la situation à fort potentiel, alors qu’elle est dégradée sur les sols de plateaux. Tous les indicateurs environnementaux considérés sont améliorés dans les deux types de milieu. Le travail permet d’identifier certains inconvénients de la protection intégrée, liés à l’augmentation de la charge de travail et à la complexité de gestion des systèmes.Avec les résultats obtenus et les méthodes proposées, le travail alimente les débats sur la durabilité des systèmes agricoles dans le domaine des grandes cultures
The agriculture in France is under intense pressure. Farmers are asked to change their crop management, to evolve toward agroecology, to follow the principles of Integrated Pest Management (IPM) and to reduce pesticide use. However such an evolution toward an alternative agricultural model will be possible only if innovative cropping systems are able to maintain competitive and profitable farms.The aim of our work is to contribute to the debates about this issue, by evaluating ex ante the potential consequences of adopting the principles of IPM over one whole agricultural region, taking into account the diversity of production situations within this region. We considered the Burgundy region for several reasons. This region has many experimental resources and available expertise on IPM. This agricultural area also has few but contrasted production situations. Both economic and environmental issues were considered.First, we studied the diversity of production situations and of cropping systems in the area, based on agricultural data sets, and we showed to what extent cropping systems are determined by the context. Then we developed a method to design fictive cropping systems, based on the optimisation of profitability while fulfilling the principles of IPM, and considering the constraints of the production situation. We used the GAMS software to implement this method based on linear programming. The method was tested on two contrasted production situations, namely the lowlands with high agricultural potential and no livestock, and the shallow soils of the plateau. We evaluated the generated cropping systems for a range of criteria covering different issues of sustainability, and we compared the performances to those of current cropping systems in these areas.Results corroborated that IPM-based cropping systems would be different in contrasted production situations. Profitability would be improved in the lowlands with high agricultural potential, whereas it would be negatively affected in the shallow soils of the uplands. All the environmental indicators that we used would be improved in both situations. Our work identified hindrances for the development of IPM, related for example to the increase in the workload at the farm level, and the increase in the system complexity.Both methods that we developed and the results we obtained should contribute to the current debates about the possible transition of arable cropping toward sustainability

Assignment (MSc) -- University of Stellenbosch, 2004.
ENGLISH ABSTRACT: In an integrated crop-livestock production farm, the profitability and sustainability of farm production is dependent on the crop rotation strategy applied. Crop rotations have historically been applied to maintain long-term profitability and sustainabiliry of farming production by exploiting the jointly beneficial interrelationships existing among different crop types and the animal production activity. Monocrop (specifically wheat) growers in the Swartland area of the Western Cape are struggling to maintain long-term profitability and sustainability of the crop production, challenging them to rethink about the introduction crop rotation in the production planning. By making proper assumptions, this paper develops a mixed integer linear programming model to suggest a decision planning for the farm planning problem faced by an integratedcrop- livestock production farmer. The mathematical model developed includes crop production, dairy production and wool sheep production activities, which permitted the consideration of five crop types within a crop rotation system. By assuming that a farmer uses a cycle of at most three years, the crop rotation model was incorporated in the composite mixed integer linear farm planning model. In order to demonstrate the application of the mathematical farm planning model formulated, a case study is presented. Relevant data from the Koeberg area of the Swartland region of the Western Cape was applied. For each planning period, the model assumed that the farm has the option of selecting from any of 15 cropping strategies. A land which is not allocated to any of the 15 crop rotation strategies due to risky production situation is left as grass land for roughage purposes of the animal production. Results of the mathematical model indicated that farm profit is dependent on the cropping strategy selected. Additionally, animal production level was also dependent on the crop strategy appl ied. Furthermore, study results suggest that the profit generated from the integrated crop-livestock farm production by adopting crop rotation was superior to profit generated 1'1'0111 the farm activities which are based on monocrop wheat strategy. Empirical results also indicated that the complex interrelationship involved in a mixed crop-livestock farm operation play a major role in determining optimal farm plans. This complex interrelationships favour the introduction of crop rotation in the crop production activities of the farm under investigation. Crop production risk is the major risk component of risk the farmer faces in the farm production. In this study, risk is incorporated in the mixed integer programrnmg farm planning model as a deviation from the expected values of an activity of returns. Model solution with risk indicated that crop rotation strategy and animal production level is sensitive to risk levels considered. The Results also showed that the incorporation of risk in the model greatly affects the level of acreage allocation, crop rotation and animal production level of the farm. Finally, to improve the profitability and sustainability of the farm activity, the study results suggest that the introduction of crop rotation which consist cereals, oil crops and leguminous forages is of paramount importance. Furthermore, the inclusion of forage crops such as medics in the integrated crop livestock production is beneficial for sustained profitability from year to year.
AFRIKAANSE OPSOMMING: Wisselbou is baie belangrik om volhoubare winsgewindheid te verseker in 'n geintegreerde lewendehawe I gewasverbouing boerdery in die Swartland gebied van Wes-Kaap. "n Monokultuur van veral koring produksie het ernstige problerne vir produsente veroorsaak. In hierdie studie word 'n gemengde heeltallige liniere prograrnmerings-model gebruik om te help met besluitneming in sulke boerderye.Die wiskundige model beskou die produksie van kontant- en voer-gewasse (5 verskillende soorte) asook suiwel- en wol/vleis-produksie (beeste en skape) .Daar word aanvaar dat die boer "n siklus van hoogstens 3 jaar in die wisselbou rotasie model gebruik .. 'n Gevallestudie word gedoen met behulp van toepaslike data van 'n plaas in die Koeberg gebied. Die model aanvaar dat die produsent 'n keuse het uit 16 wisselbou strategic .Resultate toon dat winsgewindheid afhanklik is van die strategie gekies en dat wisselbou beter resultate lewer as in die geval van "n monokultuur.Dit wys ook dat die wisselwerking tussen diereproduksie en gewasproduksie baie belangrik is in die keuse van 'n optimale strategie. Die risiko in gewasverbouing is die belangrikste risiko factor vir die produsent.In hierdie studie word risiko ook ingesluit in die gemengde heeltallige model, naamlik as 'n afwyking van die verwagte opbrengs-waardes .Die model toon duidelik dat gewasproduksie en lewendehawe-produksie baie sensitief is ten opsigte van die gekose risiko vlak. Die studie toon ook dat 'n wisselbou program wat die produksie van graan (veral koring) .oliesade asook voere insluit belangrik is vir volhoubare winsgewindheid Die insluiting van klawers (bv "medics") is veral belangrik hier.

Die vermiedene tropische Entwaldung und zusätzliche Aufforstungen sind von zentraler Bedeutung für die Klimawandelvermeidung, üben aber zusätzlichen Druck auf die globalen Landressourcen zur Produktion von Nahrungsgütern, Futtermittel, Fasern, Bioenergie und Rundholz dar. Die Ziele der Studie beziehen sich auf die Analyse der Verzichtskosten in der Land- und Forstwirtschaft sowie das Potential zur Klimawandelvermeidung in globalen Wäldern durch normative und marktbasierte Klimaschutzprogramme. Das globale ökonomische Landnutzungsmodell ''Model of Agricultural Production and its Impact on the Environment'' (MAgPIE) wurde um eine konsistente Landnutzungsdatenbank und den Forstsektor erweitert. Es simuliert die räumlich-explizite Landnutzung und deren Änderungen während die Kosten land- und forstwirtschaftlicher Produktion unter gegebener Nachfrage nach Gütern geschätzt werden. Szenarien zu Klimaschutzmaßnahmen werden verglichen mit Referenzszenarien über Zeithorizonte bis zum Jahr 2100. Die Ergebnisse verweisen auf ein begrenztes Mitigationspotential normativen tropischen Waldschutzes zu geringen zusätzlichen Kosten in der Landwirtschaft. Lateinamerika profitiert von ausreichenden Landreserven und geringem Anstieg in der Güternachfrage und geringer Referenzentwaldung. Die Verlagerung von Emissionen durch regionalen Waldschutz hat Auswirkungen auf die sektoralen Produktionskosten und verringert das globale ökonomische Potential. Die Schlussfolgerungen betreffen 1) den Bedarf an substantieller Ertragssteigerung in Sub-Sahara Afrika als Voraussetzung für die erfolgreiche Umsetzung vermiedener Entwaldung, 2) die erhöhte Gefahr der Verlagerung von Emissionen aus Entwaldung durch die Umsetzung regionaler Klimaschutzprogramme und der Liberalisierung des Holzhandels, 3) das hohe ökonomische Potential integrierter Klimaschutzprogramme zu moderaten Verzichtskosten, sowie 4) die Notwendigkeit zusätzlicher Forschung bezüglich der Unsicherheiten in Parametern und Modellprozessen.
Avoiding tropical deforestation and additional afforestation are of primary importance for climate change mitigation but exert additional pressure on global land resources for the production of food, feed, fibre, bioenergy and timber. The study objectives relate to the analysis of the foregone economic benefits, the opportunity costs, in agriculture and forestry and the climate change mitigation potential of global forests in normative and market-based programmes. The global economic ‘Model of Agricultural Production and its Impact on the Environment'' (MAgPIE) has been extended by a consistent land use database and the forestry sector. It simulates spatially-explicit land use and land use changes while estimating the costs of production in agriculture and forestry to satisfy a prescribed demand. Climate change mitigation scenarios are contrasted to baselines for time horizons up to the year 2100. The results show the limited mitigation potential of normative forest conservation in tropical regions at low additional costs in agriculture. Latin America benefits from sufficient land endowments and low increases in crop demand leading to relatively low baseline deforestation. The displacement of carbon emissions between regions impacts the regional agriculture and forestry production costs and reduces the global economic potential. The conclusions pertain to the 1) need for high rates of yield increase in Sub-Saharan Africa as a precondition for successfully avoided deforestation, 2) increased threat of regional carbon emission leakage from implementing mitigation programmes and liberalized trade of timber, 3) high economic potential of climate change mitigation from integrating afforestation and avoided deforestation at moderate costs, and 4) additional research needs to account for significant uncertainties from growth and cost parameters and model processes.

Made available in DSpace on 2017-07-10T18:33:39Z (GMT). No. of bitstreams: 1 Dissertacao Fabiano Schmidt.pdf: 1597029 bytes, checksum: f49de3970e7f596acd70e2ffd21d738c (MD5) Previous issue date: 2006-03-27
The objective of this work is the optimization of the more viable model to the agricultural airplane for certain area of soybean cultivation, with possibility from decrease of costs and risks in the activity, increasing the competitiveness of the agrobusiness through the linear programming. The work presents a literature revision about the concepts of microeconomics cost, operational research and agricultural aviation. It intends a model of linear programming for choice the model of agricultural airplane of smaller cost; and makes sensibility analyses for the variables of the proposed model. The methodology used for the development of the model uses the referring data of the agricultural airplanes existent in the market among national and imported airplanes. The calculations are divided in two stages, one before the optimization and the especific optimization. The calculations made before the optimization become separated in four stages, which are: the calculation of the fixed and variable costs of each airplane model, the capacity of operational area of each model, the demanded operational rhythm and the number of necessary airplanes to the attendance of the demand. The result selected as airplane of smaller cost schedule the model AV8, with a hourly cost of US$ 323.14, with a capacity of operational area from 175,18 hectares per hour, being the cost for hectare of US$ 1.84. The result can be interesting for companies of agricultural aviation and also for producers of larger scale or group of associated producers.
O objetivo deste trabalho é a otimização do modelo de avião agrícola mais viável para determinada área de cultivo de soja, com possibilidade de diminuição de custos e riscos na atividade, aumentando a competitividade da agropecuária através da programação linear. No trabalho desenvolve-se uma revisão de literatura acerca dos conceitos microeconômicos de custo, da pesquisa operacional e da aviação agrícola. Propõe-se um modelo de programação linear para escolha do modelo de avião agrícola de menor custo; e realiza-se análises de sensibilidade para as variáveis do modelo proposto. A metodologia empregada para o desenvolvimento do modelo utiliza os dados referentes aos aviões agrícolas existentes no mercado entre aviões nacionais e importados. Os cálculos são divididos em duas etapas, uma anterior à otimização e a otimização propriamente dita. Os cálculos anteriores à otimização dividem-se em quatro estágios, quais sejam: o cálculo dos custos fixos e variáveis de cada modelo de avião, a capacidade de campo operacional de cada modelo, o ritmo operacional exigido e o número de aviões necessários ao atendimento da demanda. O resultado selecionou como avião de menor custo horário o modelo AV8, com um custo horário de US$ 323.14, com uma capacidade de campo operacional de 175,18 hectares por hora, sendo o custo por hectare de US$ 1.84. O resultado pode ser interessante para empresas de aviação agrícola e também para produtores de maior escala ou grupo de produtores associados.

La contribution des changements d’usage des sols aux émissions de gaz à effet de serre d’origine anthropique est estimée à 17% pour la décennie 2000, en grande partie liée à la déforestation. L’un des facteurs principaux de ces changements est l’expansion des terres agricoles pour les besoins locaux de développement, mais également sous l’effet des exportations stimulées par la mondialisation. Pour cette raison, des préoccupations nouvelles surgissent quant aux effets des politiques sur l’usage des sols par le biais des marchés internationaux. Ce travail présente trois illustrations concrètes où ces effets peuvent être d’ampleur conséquente : i) l’intensification de l’agriculture dans les pays en voie de développement, ii) les accords commerciaux, et iii) les politiques d’agrocarburants. Les résultats montrent que pour chacune de ces politiques, les réponses des marchés sont susceptibles de jouer un rôle déterminant dans le bilan des gaz à effet de serre. L’atténuation du changement climatique par l’intensification des cultures conduit à des réductions d’émissions, mais l’effet rebond de la demande pourrait annuler une part substantielle des bénéfices attendus sur les surfaces de terres cultivées. L’exemple d’un possible accord entre l’Union européenne et le Mercosur montre les effets négatifs que peut induire la libéralisation de certains produits agricoles, si des mesures d’accompagnement adéquates ne sont pas mises en place. Enfin, l’effet des changements indirects d’affectation des sols est susceptible d’effacer une part substantielle des réductions d’émissions alléguées aux agrocarburants. Les réponses de l’affectation des sols aux différentes politiques dépendent néanmoins de nombreux paramètres comportementaux, et il est difficile d’en fournir une estimation chiffrée précise. Plusieurs approches de modélisation sont utilisées ici pour quantifier ces effets et explorer les intervalles de confiance découlant des estimations actuelles de la littérature économétrique. La prise en compte de cette externalité dans l’évaluation des politiques publiques nécessite des approches nouvelles intégrant mieux les différents niveaux d’incertitude sur ces effets
Land use change is estimated to have generated 17% of anthropogenic greenhouse gas emissions in the 2000s, a large part coming from deforestation. The main driver of these emissions is expansion of agricultural activities, for the need of local development in tropical regions. However, they have also been caused by the dynamics of globalisation which has stimulated agricultural trade flows. Thus, today, there are new concerns with respect to how agricultural policies are influencing land use changes in other parts of the world through international market responses. In this work I consider three concrete illustrations of where these effects can be of significant magnitude: i) agriculture intensification in developing countries, ii) trade agreements, and iii) biofuel policies. I find that for each of these policies, market responses are likely to play a significant role in the final greenhouse gas emission balance. Mitigation of emissions through agricultural intensification could have quite beneficial outcomes, but the rebound effect on the demand side would offset a large part of greenhouse gas emission savings attributable to the land sparing effect. With the example of a possible EU-MERCOSUR trade agreement, I also show the adverse effect of liberalising certain specific agricultural products closely connected to land use change dynamics without adequate accompanying measures. Last, the indirect land use change effect of biofuels is likely to offset a large part of their alleged GHG emission savings. Land use change responses depend on many behavioural parameters, however, and providing precise estimates constitutes a challenge. I use different modelling approaches to quantify their magnitude and extensively explore the level of confidence on the basis of current state of econometric findings.New approaches should be elaborated to take account of this externality in public policy assessments, together with an appropriate consideration of the uncertainty ranges associated with these effects

Land is an essential resource for most types of agricultural production. Its continued productivity forms a significant part of the deliberations about sustainable agriculture. While discussing sustainable agriculture, this thesis focuses on government agricultural programmes that have influenced agricultural land use in the Peace River region of British Columbia. The general aim is to point out the relevant programmes that impede sustainability of agriculture. We assume that farmers are continually making decisions about the optimal allocation of land so as to maximise present value of net farm incomes. A linear programme (LP) is one of the techniques of mathematical programming that can be used to maximise farm incomes. It is this technique that we employed to analyze effects of government agricultural programmes on land use as it pertains to crop and forage production in the Peace River region, where for ages are assumed to be a derived demand for livestock production.Cultivation practices of summerfallow and continuous cropping are examined. Parametric linear programming (PLP) is subsequently used to analyze other optimal land use scenarios by varying the LP's objective function coefficients. As well, other cases including the elimination or halving of government subsidies are also simulated and discussed. Furthermore, an attempt was made to simulate two other scenarios that deal with the removal of grains and summerfallow from lower quality land. The region's soilerosion problem was also simulated. It was found, among other things, that four government agricultural programmes--Western Grain Stabilization Act, Special Canadian Grain Programme, Crop Insurance and Chemical Rebates--encouraged cultivation of marginal lands, which are more susceptible to erosion. For example, some 26% (comprising wheat and summerfallow) of the total farm acreage occurred on classes 4and 5 land. Consequently, these programmes, as presently constituted, adversely impact on Peace River region's sustainable agriculture. Cultivation of grains on only good quality lands resulted in a significant reduction of summerfallow and more intensive cropping, which will lead to less soil degradation in the region. This alternative programme also was observed to increase a farmer's income by about 4%, which can add a total of over $259,000 to the region's economy. As well, it can increase pasture to feed more than 15,600 beef cows, which will be a boon to the livestock industry in the region.

Economic changes such as rising açaí prices and the availability of off-farm employment are transforming the landscape of the Amazonian várzea, subject to decision-making at the farming household level. Land use change results from complex human-environment interactions which can be addressed by an agent-based model. An agent-based model is a simulation model composed of autonomous interacting entities known as agents, built from the bottom-up. Coupled with cellular automata, which forms the agents’ environment, agent-based models are becoming an important tool of land use science, complementing traditional methods of induction and deduction. The decision-making methods employed by agent-based models in recent years have included optimization, imitation, heuristics, classifier systems and genetic algorithms, among others, but multiple methods have rarely been comparatively analyzed. A modular agent-based model is designed to allow the researcher to substitute alternative decision-making methods. For a smallholder farming community in Marajó Island near Ponta de Pedras, Pará, Brazil, 21 households are simulated over a 40-year period. In three major scenarios of increasing complexity, these households first face an environment where goods sell at a constant price throughout the simulated period and there are no outside employment opportunities. This is followed by a scenario of variable prices based on empirical data. The third scenario combines variable prices with limited employment opportunities, creating multi-sited households as members emigrate. In each scenario, populations of optimizing agents and heuristic agents are analyzed in parallel. While optimizing agents allocate land cells to maximize revenue using linear programming, fast and frugal heuristic agents use decision trees to quickly pare down feasible solutions and probabilistically select between alternatives weighted by expected revenue. Using distributed computing, the model is run through several parameter sweeps and results are recorded to a cenral database. Land use trajectories and sensitivity analyses highlight the relative biases of each decision-making method and illustrate cases where alternative methods lead to significantly divergent outcomes. A hybrid approach is recommended, employing alternative decision-making methods in parallel to illustrate inefficiencies exogenous and endogenous to the decision-maker, or allowing agents to select among multiple methods to mitigate bias and best represent their real-world analogues.

碩士
國立屏東科技大學
工業管理系所
96
Characterized as rich mineral substances, low temperature, few bacteria, and stability with numerous implementation aspects on aquaculture, food, drinking, and leisure, the deep sea water (DSW) development has become a new industry in Taiwan. Although the deep sea water can be used for many types of industries, but because of lacking an effective integration of system and industrial efficiency level, the industry has been unable to smoothly promote. This research is with the economic analysis of the temperature-controlled agriculture manufacturers into deep sea biological technology parks as the research topics, formed a investment decision-making. Construction of the model based on original multi-objective linear programming (MOLP) model, combines with the fuzzy theory, the model will be converted to fuzzy multi-objective linear programming (FMOLP) model to construct the valuation mode of the manufacturers investment performance. Case proved, with high economic value of the flowers for the study, and advances the specific conclusions and recommendations for follow-up affiliated research of scholars and reference of the actual application.