Made available in DSpace on 2015-03-26T13:53:15Z (GMT). No. of bitstreams: 1 texto completo.pdf: 3282351 bytes, checksum: 4bd030dea9fc0164a13290e835c7c301 (MD5) Previous issue date: 2010-02-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Agriculture is an economic activity depends, in large part, the physical environment. The ecological aspect confers fundamental importance to the process of agricultural production. A country or region has several sub-regions with different soil conditions and climate, and therefore with different skills to produce various agricultural goods. Interpretation of ground surveys is to be of significant importance for the use of this natural resource in agriculture and other sectors that use the soil as an integral element of their activities. When it comes to agricultural activities, these interpretations can help to classify land according to their suitability for different crops under different management conditions and feasibility of improvement through new technologies. It can still be considered in the interpretation of ground surveys, the needs for fertilizer and lime, which enable evaluation of potential inputs depending on the acreage in the country. The system of evaluation of land suitability in Brazil began in the 1960s as an effort to classify the potential of tropical lands for agriculture. In pursuit of knowledge of land suitability of Brazil, the Evaluation System of agricultural land suitability (Ramalho Filho and Beek, 1995) has been employed by more be a major tool for understanding the potential and the availability of land in accordance with different levels of technology or management, and the method recommended by Embrapa. Index Geographic and Technological Development (GEOTEC) was prepared from three other indices: the Fitness Index Fund (IAG), the Index Technology (SIT) and the Water Index (IHI). Fontes et al (2008) tested different combinations of the three sub-indices used in their work and reached the following calculation: Geotec = (IAG * 40%) + (ITE * 40%) + (IHI * 20%). For this work we built the index Geographic and Technological II (GEOTEC II), which is made from two other indices: the Fitness Index Fund (IAG) and Index Technology (ITE).The combination proposed for this new index results in the following calculation: Geotec II = (IAG * 50%) + (ITE * 50%). These indices consist of aggregation of geographical variables, assets and liabilities whose relevance is based in the analysis of the determinants of income and growth potential in the context of natural as well as the analysis of economic and social variables. As this work is pervaded units federation of Brazilian territory, the clipping mesorregional was the most appropriate, having been working with mapping "of Brazil macroecological Design" produced by Embrapa (National Survey and Soil Conservation - SNLCS) between the years 1992/93. The objectives of this study were: construction of indices of agricultural suitability (IAG) and technological index (ITE) of meso Brazilian-purpose support of initiatives that enable the development of agricultural regions, and identify the technologies that had the greatest association with the production of different cultures. The highest values of ITE are located in the regions Araraquara / SP, West of Santa Catarina and Rio Grande northwest while the lowest values of ITE located in the regions Marajó / PA, North and South Amazonas Pará. IAG for the highest values are found in Southeast and South and lowest in the North. It was found that the control of pests and diseases is a technology that needs to be more widespread throughout the territory, since only 30% of properties in the country to use, with greater concentration in the states of Goias and Minas Gerais. The highest percentage of use of fertilizer and lime, and tillage is located in the center-south axis of the country, the latter being little used technology in the north. / A agricultura é uma atividade econômica dependente, em grande parte, do meio físico. O aspecto ecológico confere fundamental importância ao processo de produção agropecuária. Um país ou região apresenta várias sub-regiões com distintas condições de solo e clima e, portanto, com distintas aptidões para produzir diferentes bens agrícolas. A interpretação dos levantamentos de solo constitui-se de importância significativa para a utilização racional desse recurso natural na agricultura e em outros setores que se utilizam do solo como um elemento integrante de suas atividades. Em se tratando de atividades agrícolas, estas interpretações podem auxiliar na classificação de terras de acordo com sua aptidão para as diversas culturas, sob diferentes condições de manejo e viabilidade de melhoramento através de novas tecnologias. Pode-se ainda considerar, na interpretação dos levantamentos de solo, as necessidades de fertilizantes e corretivos, que possibilitam a avaliação potencial dos insumos em função da área cultivada no país. O sistema de avaliação da aptidão agrícola, no Brasil, teve início na década de 1960 como esforço em classificar o potencial das terras para a agricultura tropical. Na busca do conhecimento da aptidão das terras do Brasil, o Sistema de Avaliação da Aptidão Agrícola das Terras (Ramalho Filho & Beek, 1995) tem sido o mais empregado por consistir num importante instrumento para conhecimento do potencial e da disponibilidade de terras, de acordo com diferentes níveis de tecnologia ou de manejo, sendo o método preconizado pela Embrapa. O Índice Geográfico e Tecnológico (GeoTec) foi elaborado a partir de três outros índices: o Índice de Aptidão Agrícola (IAG), o Índice Tecnológico (ITE) e o Índice Hídrico (IHI). Fontes et al (2008) testaram diferentes combinações entre os três sub-índices utilizados em seu trabalho e chegaram ao seguinte cálculo: GeoTec= (IAG * 40%) + (ITE * 40%) + (IHI * 20%). Para este trabalho foi construído o Índice Geográfico e Tecnológico II (GeoTec II), sendo este elaborado a partir de dois outros índices: o Índice de Aptidão Agrícola (IAG) e o Índice Tecnológico (ITE). A combinação proposta para este novo índice resulta no seguinte cálculo: GeoTec II= (IAG * 50%) + (ITE * 50%). Esses índices consistem da agregação de variáveis geográficas, ativas e passivas cuja relevância está pautada na análise dos determinantes de renda e de crescimento no contexto das potencialidades naturais, bem como na análise de variáveis econômicas e sociais. Como este trabalho se perpassou nas unidades de federação do território brasileiro, o recorte mesorregional foi o mais adequado, tendo-se trabalhado com o mapeamento “Delineamento Macroecológico do Brasil” produzido pela Embrapa (Serviço Nacional de Levantamento e Conservação dos Solos – SNLCS) entre os anos de 1992/93. Os objetivos do presente trabalho foram: construção dos índices de aptidão agrícola (IAG) e índice tecnológico (ITE) das mesorregiões brasileiras com finalidade de subsidiar iniciativas que permitam o desenvolvimento agrícola das regiões, além de identificar as tecnologias que apresentaram maior associação com a produção das diferentes culturas. Os maiores valores do ITE estão situados nas mesorregiões Araraquara/SP, Oeste Catarinense e Noroeste Rio Grandense ao passo que os menores valores do ITE localizam-se nas mesorregiões Marajó/PA, Norte Amazonense e Sudoeste Paraense. Para o IAG os maiores valores são encontrados nas regiões Sudeste e Sul e os menores na região Norte. Constatou-se que o controle de pragas e doenças é uma tecnologia que precisa ser mais difundida em todo o território, visto que apenas 30% das propriedades do país a utilizam, com maior concentração nos Estados de Goiás, São Paulo e Minas Gerais. A maior porcentagem de utilização de adubos e corretivos e preparo do solo está situada no eixo Centro-Sul do país, sendo esta última tecnologia pouco utilizada no Norte do país.

Méconnues et vouées à disparaître par les politiques de modernisation agricoles françaises et européennes, les petites exploitations agricoles (identifiées par les services statistiques comme les exploitations ayant une production brute standard de moins de 25000 €) sont toujours présentes dans le paysage agricole français. En 2010, le recensement agricole en comptabilise près de 178 000 soit plus de 36% des exploitations agricoles de la métropole française. Le premier chapitre de la thèse dresse un tableau statistique des petites exploitations agricoles et les compare aux moyennes et grandes exploitations. Il montre que les petites exploitations sont dirigées par des exploitants en général peu formés et âgés, qui passent en moyenne, un mi-temps sur l’exploitation et ont peu de main d’oeuvre supplémentaire. Dans le second chapitre on réalise une typologie d’après une méthode de classification mixte. Celle-ci permet de regrouper les petites exploitations agricoles en cinq grands groupes et d’en déduire des stratégies potentielles développées par ces exploitations. Elles sont confirmées en partie, par l’étude des trajectoires de petites exploitations à partir de l’appariement partiel des recensements agricoles de 2000 et 2010. On montre que se côtoient au sein des petites exploitations agricoles des exploitants proches de la cessation d’activités, des exploitants en phase d’installation ainsi que des exploitants pour qui être petit n’est pas transitoire. L’analyse statistique est complétée dans le troisième chapitre par des enquêtes de terrain. La première est réalisée en zone défavorisée dans les Baronnies des Pyrénées, la seconde dans le périurbain de Montpellier. On s’appuie sur les résultats de ces enquêtes, croisés aux données statistiques du recensement agricole de 2010 pour évaluer les contributions environnementales, sociales et économiques des petites exploitations agricoles. Le quatrième chapitre est centré sur la Politique Agricole Commune. Avec l’élargissement de l’UE, les petites exploitations agricoles ont trouvé une place dans le discours politique. On revient sur l’adaptation des aides de la PAC 2014-2020 aux petites exploitations agricoles. Nous étudions l’intérêt d’un dispositif de simplification passant par une aide forfaitaire inconditionnelle, des politiques d’incitation à la création d’emploi dans les petites exploitations agricoles, et des mesures pour faciliter les installations tardives et l’accès au foncier. / Small farms (identified by statistical services as farms with a standard output of less than 25000€) are relatively unknown and condemned to disappear by French and European agricultural modernization policies. In the 2010 agricultural census, 178 000 farms are counted as small farms, representing more than 36% of metropolitan French farms. In the first chapter, we present a statistical description of small farms in comparison with medium and large farms. Small farms are mostly run by elderly farmers with low levels of education/training who work half-time on the farm and have little additional workforce. In the second chapter, we implement a typology of small farms using a mixed classification method. We obtain five different groups and deduce potential strategies developed by small farms. These strategies are partially confirmed by the study of different small farms trajectories between 2000 and 2010. We find farmers close to cessation of farming, as well as farmers in the setting-up stage and farmers who are not in a transition phase. This statistical analysis is completed in the third chapter by field surveys. The first survey is administered in less favored areas of the Baronnies of the Pyrénées, and the second one in the peri-urban area of Montpellier. These surveys are complemented by statistical data from the 2010 agricultural census to assess the environmental, social and economic contributions of small farms. The fourth chapter focuses on the Common Agricultural Policy. With the enlargement of the EU, small farms found a place in political discourse. We suggest ways of adapting the 2014-2020 CAP support schemes to small farms. We study the Small Farms Scheme and its advantages as a simplified scheme involving an unconditional flat-rate. We then review measures to favour employment in small farms and measures to facilitate setting-up and access to agricultural land.

In recent years there has been an increasing awareness of the detrimental influence of diffuse sources of pollution on aquatic systems and of the integral role played by sediment in the mobilisation and transport of pollutants. The recognition of the environmental, societal and economic importance of the ecological health of aquatic environments has led to a change in emphasis regarding agricultural and environmental policy. To implement successful delivery of emerging policy requirements, there is a current need to have an enhanced understanding of the relationship between different forms of land use and sources of diffuse pollution, particularly sources of fine sediment. To understand the potential impacts of future land use changes, including environmental conservation measures on sources of sediment, it is useful to consider them within a longer-term context. This study has successfully applied the sediment source fingerprinting technique to floodplain overbank sediment cores in a retrospective study of six diverse UK river catchments with identified sediment problems. The varying estimates of relative sediment contributions from differing sources have been compared to known land use change in the study catchments over concurrent time periods, to explore any associations which might be apparent. Over the last 40 years, the increased cultivation of high erosion risk crops, such as those which are harvested late in the season (e.g. maize) and those which are sown in the autumn (e.g. winter wheat), has contributed disproportionately to the total sediment load relative to the area of land occupied by such cultivation. Increased stocking densities have resulted in increased relative sediment contributions from grassland sources, particularly intensively managed temporary grassland, but can have an even greater impact on sediment contributions derived from channel bank sources. The installation and maintenance of drainage for agriculture or for flood risk management has resulted in increased relative sediment loads from channel bank and associated sub-surface sources. Through the further development of such research, the efficacy of mitigation measures can be tested against evidence-based historic trends and those management approaches which provide identifiable improvements can be developed as best practice options for future land management targeted at reducing the negative impacts of excessive sediment ingress to river systems. The design of the source fingerprinting methodology used in this work was based on an established successful approach and this was developed further through the incorporation of a number of refinements designed to improve the robustness of the technique and expedite its implementation.

L’objectif principal de cette thèse est d’instruire l’organisation des successions culturales, à l’échelle de la France et sur un recul décennal, tant en terme de cinétiques localisées qu’en terme de dynamiques liées à des variables explicatives du milieu physique et socio-technico-économiques. Ce travail de « fouille de données » est appliqué en France métropolitaine, en utilisant les bases de données publiques disponibles. Notre étude couvre la période 1992-2003 où s’implémenta la réforme de 1992 de la Politique Agricole Commune européenne et l’agenda 2000 en France. A partir d’une fouille de données sur l’ensemble des points Terruti sur cette période, 2549 successions culturales de trois ans furent identifiées. Ensuite, 21 clusters de l’ensemble des 430 régions agricoles (RA) françaises, quatre systèmes de culture, 90 RA, parangons des 430 RA, et trois régions principales appartenant à cinq des 21 clusters, regroupant les cultures de céréales, oléagineux et protéagineux, ont été définis. Deux approches de cinétiques des successions ont été réalisées : Une étude envisageant les successions de culture qui suivent les retournements de prairies permanentes. Une recherche des dynamiques d’évolution de successions culturales en lien avec des conditions externes. Nous proposons une utilisation ultérieure des méthodes mobilisées qui ont montré leur capacité à cartographier les grandes tendances d’évolution en France et à identifier les principales variables explicatives de ces évolutions. Les apports de cette thèse contribuent à améliorer notre compréhension des processus qui organisent les successions culturales en France et construisent par ces pratiques agricoles très dynamiques des impacts forts sur le territoire agricole français / In the context of changing agricultural policy, the development of agricultural production systems, increasing concern for agricultural sustainability and shifts in agricultural land management practice-related land-use change, the main objective of this thesis was to mine crop sequence patterns (CSP) and the relationships between CSP and the biophysical and socio-technical-economic conditions in mainland France from historical census data (e.g. land-cover survey, agricultural censuses, population census). Our study period 1992-2003 covers the implementation period of the 1992 European Union Common Agricultural Policy reform and Agenda 2000 in France. Both the classical statistical and data mining technique were applied in alone or combined ways in this thesis. First, we proposed an innovative approach to representing CSP within a given area and period at a large regional scale in a stationary way. The 2549 3-year crop sequences (CSs) were first identified as major CSs within all 430 agricultural districts (ADs) in mainland France during this period. Next, 21 clusters of ADs , four types of cropping systems, 90 representative ADs and three principal planting zones of cereals, oilseeds, and protein crops belonging to five clusters identified previously were further defined. We then explored CSP in a dynamic way by investigating CSP after grassland-to-cropland conversion, the temporal variability of CSP, and the evolution of the relationships between CSP and the external conditions over the study period. We conclude that the approaches developed here permit the representation of CSP at the large regional scale in both stationary and dynamic ways using time series land-cover data denoting specific agricultural cover types. The findings of this thesis contribute to improving the understanding of the process and pattern of human land management practices by agriculture affecting the terrestrial biosphere