To assess the accuracy of the second-generation Prairie Agrometeorological Model (PAM2nd) as an agrometeorological model for spring wheat on the Canadian Prairies, a study was conducted to validate the model using field measurements. Results from model validation indicated soil moisture was being overestimated at most sites during the second half of the growing season, while soil moisture was underestimated during periods that experienced consecutive days of rainfall. Modifications to the model were implemented to improve the model's ability to simulate soil moisture. Evapotranspiration estimates from PAM2nd and the FAO56 Penmen-Monteith method were compared to water balance methods. Both models produced estimates that fell within the range of water balance ET measurement error. The similarity in performance of both models to estimate ET compared to the water balance ET means the adoption of either model could be justified. However, PAM2nd would be more appropriate because it requires fewer, more commonly measured, surface weather parameters. / February 2009

To assess the accuracy of the second-generation Prairie Agrometeorological Model (PAM2nd) as an agrometeorological model for spring wheat on the Canadian Prairies, a study was conducted to validate the model using field measurements. Results from model validation indicated soil moisture was being overestimated at most sites during the second half of the growing season, while soil moisture was underestimated during periods that experienced consecutive days of rainfall. Modifications to the model were implemented to improve the model's ability to simulate soil moisture. Evapotranspiration estimates from PAM2nd and the FAO56 Penmen-Monteith method were compared to water balance methods. Both models produced estimates that fell within the range of water balance ET measurement error. The similarity in performance of both models to estimate ET compared to the water balance ET means the adoption of either model could be justified. However, PAM2nd would be more appropriate because it requires fewer, more commonly measured, surface weather parameters.

To assess the accuracy of the second-generation Prairie Agrometeorological Model (PAM2nd) as an agrometeorological model for spring wheat on the Canadian Prairies, a study was conducted to validate the model using field measurements. Results from model validation indicated soil moisture was being overestimated at most sites during the second half of the growing season, while soil moisture was underestimated during periods that experienced consecutive days of rainfall. Modifications to the model were implemented to improve the model's ability to simulate soil moisture. Evapotranspiration estimates from PAM2nd and the FAO56 Penmen-Monteith method were compared to water balance methods. Both models produced estimates that fell within the range of water balance ET measurement error. The similarity in performance of both models to estimate ET compared to the water balance ET means the adoption of either model could be justified. However, PAM2nd would be more appropriate because it requires fewer, more commonly measured, surface weather parameters.

Made available in DSpace on 2016-08-10T10:49:46Z (GMT). No. of bitstreams: 1 Pedro Ramos Lima.pdf: 5624359 bytes, checksum: 2e0bb0a3f44b3bf33e0a2a9e5aefca19 (MD5) Previous issue date: 2011-09-30 / From the Green Revolution took place in the world, and especially since the year 1970 in Brazil, with the use of machinery and chemicals, agricultural changes occurred globally and nationally. New áreas were occupied in Brazil, opening new frontiers for agriculture, which began to develop new crops. This work aims to show the changes occurring in the Cerrado of Goiás from state interference in agriculture, with programs, investments, research and technology allowed the creation of big business to serve the southern and external markets. The focus is to show that economic growth occurred as a result of economic development. Research shows that this is an unsustainable model of agriculture in social and environmental issue, with the contradiction between the rate of economic growth and social development. It was a conservative modernization, further concentrating land and income in the region. It occurred to urbanization of the rural exodus to cities, where the population excluded from the field moved to the cities, increasing poverty and misery in the urban centers. As a result, there was the occurrence of economic growth, increasing GDP and Trade Balance of the State of Goiás, with no economic development. That is, the agricultural model implemented has brought social and environmental burden. To address these social burdens were studied 10 municipalities with the highest agricultural VA, 2008, based on Census 2000 and 2010, where he observed the occurrence of the rural exodus at all, and no increase of poverty, since income average of these municipalities was increasing, and urban incomes than rural, with some exceptions. The age of the rural population above 50 years increased, with the young going to the cities. In all municipalities informal employment is higher than 40%, exceeding 50% in some. And the environmental burden is seen as the destruction of the headwaters of rivers, soil solidification, the indiscriminate use of water, among others. It is a historical approach with the use of material already published separately, which will be collected so that you can get a more comprehensive view of this context. / A partir da Revolução Verde ocorrida no mundo, e especialmente a partir dos anos 1970 no Brasil, com a utilização de máquinas e produtos químicos, ocorreu mudanças na agricultura mundial e nacional. Novas áreas foram ocupadas no Brasil, abrindo novas fronteiras para a agricultura, que passou a conceber novas culturas. Este trabalho visa mostrar as transformações ocorridas no Cerrado goiano a partir da interferência do Estado na agricultura, que com programas, investimentos, pesquisas e tecnologia que permitiu a criação do grande negócio para atender ao mercado sulino e externo. O foco é mostrar que em conseqüência ocorreu crescimento econômico sem desenvolvimento econômico. A pesquisa demonstra que se trata de um modelo agrícola insustentável na questão socioambiental, com contradição entre os índices de crescimento econômico e os de desenvolvimento social. Tratou-se de uma modernização conservadora, concentrando ainda mais as terras e a renda da região. Ocorreu a urbanização das cidades com o êxodo rural, onde a população excluída do campo mudou-se para as grandes cidades, aumentando a pobreza e miséria nos centros urbanos. Como consequência, houve a ocorrência de crescimento econômico, com aumento do PIB e da Balança Comercial do Estado de Goiás, sem que houvesse desenvolvimento econômico. Ou seja, o modelo agrícola implantado trouxe consigo um ônus social e ambiental. Para responder a esses ônus sociais foram estudados os 10 municípios com maiores VA agropecuários de 2008, com base nos Censos de 2000 e 2010, onde se pôde observar a ocorrência do êxodo rural em todos, e que não houve aumento da pobreza, pois a renda média desses municípios foi crescente, sendo a renda urbana superior a rural, com algumas exceções. A idade da população rural acima de 50 anos foi crescente, com o jovem indo para os centros urbanos. Na totalidade dos municípios o emprego informal é superior a 40%, sendo superior a 50% em alguns deles. E, os ônus ambientais observados é quanto à destruição das nascentes dos rios, a solidificação dos solos, a utilização indiscriminada das águas, entre outros. Trata-se de uma abordagem histórica com utilização de materiais já publicados isoladamente, que serão reunidos de forma que possa obter uma visão com maior abrangência desse contexto.

L'Union Européenne a un programme ambitieux pour faire face aux effets du changement climatique, les institutions européennes devant désormais prendre en compte l'environnement dans le cadre de ses politiques. L'objectif de ma thèse consiste à évaluer les impacts des politiques publiques européennes sur l'agriculture et l’environnement, de mesurer leurs effets croisés et d'évaluer l'intérêt d'une meilleure coordination de ces politiques. La thèse vise à enrichir l'analyse économique sur des problématiques importantes recentrées sur la réduction des émissions de gaz à effet de serre (GES) agricoles dans l'UE et le niveau de la production agricole, sous un angle quantitatif. La méthodologie repose sur un modèle de programmation mathématique qui simule l’offre agricole européenne (AROPAj), utilisant les données du Réseau d'Information Comptable Agricole. L'analyse est réalisée à plusieurs niveaux, européen, national, régional et infra-régional, tenant compte de la variabilité du contexte économique qui caractérise l'agriculture européenne sur les six années 2007-2012. Nous évaluons tout d'abord comment l'agriculture peut contribuer à l'atténuation des émissions de GES dans l'UE et nous offrons une analyse détaillée des courbes de coûts marginaux d'abattement. Les résultats indiquent qu’en moyenne, sur la période 2007-2012, l’agriculture européenne peut réduire ses émissions d’environ 10%, 20% et 30% respectivement, pour les prix des émissions de 38, 112.5 et 205 Euros/tCO2eq. Nous montrons que l’agriculture peut offrir une atténuation substantielle et que le potentiel et les coûts d’atténuation varient substantiellement dans le temps et dans l’espace. La deuxième problématique étudiée porte sur la compatibilité entre l’augmentation de la production agricole et la diminution de l’impact de l’agriculture sur l’environnement. En introduisant une approche primale (via un prix du carbone) et une approche duale (via un objectif calorique), nous montrons qu’on peut réduire les émissions de GES et modifier l’offre agricole tout en augmentant la quantité en calories alimentaires. On étend la problématique des émissions de GES, en dissociant les prix des deux gaz (CH4 et N2O). Un système de prix différenciés permet de mieux adapter la politique de régulation climatique en fonction de l'horizon de temps sur lequel on se projette, offrant une flexibilité dans la réduction des coûts d’abattement des émissions. / The European Union has an ambitious agenda to deal with the effects of climate change, the European institutions must now take environment into account within the framework of its policies. The objective of my thesis is to evaluate the impacts of European public policies on agriculture and environment, to measure their crossed effects and to assess the potential for a better coordination of these policies. The thesis aims to enrich the economic analysis on important issues refocused on the reduction of agricultural greenhouse gas emissions in the EU and the level of agricultural production, from a quantitative perspective. The methodology is based on a mathematical programming model that simulates the European agricultural supply (AROPAj), using data from the Farm Accountancy Data Network. The analysis is carried out at several levels, European, national, regional and sub-regional, taking into account the variability of the economic context that characterizes the European agriculture over the six years 2007-2012. We first assess how agriculture may contribute to the mitigation of EU GHG emissions and provide a detailed analysis of marginal abatement cost curves. The results show that, on average, over the period 2007-2012, EU agriculture may reduce its emissions by around 10%, 20% and 30%, respectively for emission prices of 38, 112.5 and 205 EUR/tCO2eq. We show that agriculture may offer substantial mitigation and that mitigation costs and potential vary in time and in space. The second issue studied concerns the compatibility between the increase in agricultural production and the reduction of the impact of agriculture on the environment. By introducing a primal approach (via a carbon price) and a dual approach (via a calorie target), we show that we can reduce GHG emissions and change agricultural supply while increasing the quantity of food calories. We extend the issue of GHG emissions by separating the prices of the two gases (CH4 et N2O). A differentiated price system allows to better adapt the climate regulation policy according to the time horizon on which we are projected, offering flexibility in reducing the emission abatement costs.

Orientador: Bernardo Mançano Fernandes / Resumo: A agricultura capitalista brasileira sempre esteve voltada para atender as demandas do mercado externo, apoiada em pilares que cumprem função de oferecer matéria-prima e disponibilizar mão de obra barata para a indústria. Estes pilares estão baseados na concentração da terra, no modelo agroexportador, na expropriação camponesa e na exploração do trabalho. Este modelo de produção intensifica a utilização do solo e o uso descontrolado de agrotóxicos, preocupando-se, exclusivamente, com a produtividade e o lucro. Na pós-revolução verde, o modelo capitalista de produção proporcionou inovações tecnológicas no campo com a introdução de novos insumos agrícolas, máquinas modernas e modificação genética das sementes. Porém, estas mudanças agrícolas somente se viabilizaram, pois os grandes latifundiários se apoderaram de créditos públicos subsidiados. Por outro lado, a agricultura não capitalista, baseada no trabalho familiar, ocupando áreas periféricas no meio rural e com baixa inovação tecnológica, é a principal responsável pela produção de alimentos e dos empregos no campo. Os camponeses utilizam a terra para produzir sua subsistência, bem como produzir alimentos para o conjunto da sociedade. A pesquisa mostrou que as áreas de reforma agrária contribuem para a produção de alimentos nos diferentes aspectos, seja para subsistência das famílias assentadas, seja para produção, industrialização e comercialização de alimentos para a população rural e urbana. No entanto, existem contradiçõ... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre