Um die anderen Arten von Veröffentlichungen zu diesem Thema anzuzeigen, folgen Sie diesem Link: Agricultural pattern.
Dissertationen zum Thema „Agricultural pattern“
Geben Sie eine Quelle nach APA, MLA, Chicago, Harvard und anderen Zitierweisen an
Machen Sie sich mit Top-50 Dissertationen für die Forschung zum Thema "Agricultural pattern" bekannt.
Neben jedem Werk im Literaturverzeichnis ist die Option "Zur Bibliographie hinzufügen" verfügbar. Nutzen Sie sie, wird Ihre bibliographische Angabe des gewählten Werkes nach der nötigen Zitierweise (APA, MLA, Harvard, Chicago, Vancouver usw.) automatisch gestaltet.
Sie können auch den vollen Text der wissenschaftlichen Publikation im PDF-Format herunterladen und eine Online-Annotation der Arbeit lesen, wenn die relevanten Parameter in den Metadaten verfügbar sind.
Sehen Sie die Dissertationen für verschiedene Spezialgebieten durch und erstellen Sie Ihre Bibliographie auf korrekte Weise.
1
Haslem, Angie, und angie haslem@deakin edu au. „Landscape Pattern, Countryside Heterogeneity and Bird Conservation in Agricultural Environments“. Deakin University. Life and Environmental Sciences, 2008. http://tux.lib.deakin.edu.au./adt-VDU/public/adt-VDU20090114.101341.
Der volle Inhalt der QuelleAnnotation:
Agricultural environments are critical to the conservation of biota throughout the world. This is due both to the limited extent of current reserve systems and the large, and still expanding, proportion of terrestrial environments already dominated by agricultural land-uses. Consequently, there is a growing call from scientists around the world for the need to maximise the conservation value of agricultural environments. Efforts to identify key influences on the conservation status of fauna in agricultural landscapes have taken complementary approaches. Many studies have focussed on the role of remnant or semi-natural vegetation, and emphasised the influence on biota of spatial patterns in the landscape. Others have recognised that many species use diverse countryside elements (matrix habitats) within farmland, and emphasise the benefits of landscape heterogeneity for conservation. Here, these research themes have been combined. This study takes a whole-of-landscape approach to investigating how landscape pattern and countryside heterogeneity influence the occurrence of birds in agricultural environments. Birds were sampled in 27 agricultural mosaics, each 1 km x 1 km in size (100 ha), in Gippsland, south-eastern Australia. Mosaics were selected to incorporate variation in two landscape properties: the cover of native vegetation, and richness of different types of element (i.e. land-uses/vegetation types). In each mosaic, 15 fixed sampling locations were stratified among seven different elements in proportion to their cover in the mosaic: native vegetation, linear vegetation, tree plantation, scattered paddock trees, pasture, wetlands and farm dams. Six point counts of birds were undertaken at all sample points in each mosaic: three each in the breeding and non-breeding months of a one-year period (October 2004 August 2005). Independent measures of the composition, configuration, and heterogeneity of elements in the mosaic had differing effects on the richness of bird species recorded in these same mosaics. Sub-groups of birds based on habitat requirements responded most strongly to the extent of preferred element types in mosaics. Woodland birds (those of greatest conservation concern in farmland environments in Australia) were richer in mosaics with higher cover of native vegetation while open-tolerant species responded to the extent of scattered trees. In contrast, for total species richness, mosaic heterogeneity (richness of element types) and landscape context (cover of native vegetation in surrounding area) had the greatest influence. Mosaic structural properties also influenced the composition of entire bird assemblages in study mosaics. Avifaunal composition showed systematic variation along two main gradients which were readily interpreted in relation to landscape properties: 1) a gradient in the cover of wooded vegetation and, 2) the proportional composition of vegetation types in the mosaic. These gradients represent common trajectories of landscape modification associated with agricultural development: namely, the removal of wooded vegetation and the replacement of native species with exotic vegetation (e.g. crops and plantations). Species possessing different characteristics in relation to three avian life-history traits (nest type, feeding guild and clutch size) varied significantly in their position along these gradients of landscape modification. Species with different nesting requirements showed a strong relationship with the gradient in wooded vegetation cover while species belonging to different feeding guilds were influenced by the gradient defined by the replacement of native vegetation with exotic species. More bird species were recorded in native vegetation than in any other type of element sampled in this study. Nevertheless, most countryside elements had value for many species; particularly structurally complex elements such as scattered trees and tree plantation. Further, each type of landscape element contained different bird assemblages. Species that were recorded in a greater number of different types of landscape element were also recorded in more mosaics. This was true for all species and for woodland birds, and indicates that species that can use a greater range of countryside elements may have an increased tolerance of future landscape modification. The richness of woodland species at survey sites in different elements was influenced by features of the mosaic in which they occurred. Notably, the richness of woodland bird species recorded at sites in scattered trees and pasture increased with a greater cover of native vegetation in the overall mosaic. Of the overall pool of woodland bird species documented in the broader study region, 35% of species were not recorded in the agricultural mosaics sampled here. While many of these species were uncommon in the study area, or were associated with vegetation communities infrequently sampled in mosaics, this shows that conservation efforts in agricultural landscapes will not be appropriate for all species. For those woodland species that were recorded, measures of the extent of wooded vegetation cover had a strong, positive influence on the frequency of occurrence of individual species in mosaics. Thus, individual species of woodland bird occurred more frequently in mosaics with a greater cover of wooded vegetation. Nine woodland species showed a stronger response to measures of vegetation cover that included tree plantation and/or scattered trees than to the cover of native vegetation alone. For these species, structurally complex countryside elements provide valuable supplementary habitat at the landscape scale. Results of this study show that landscape properties influence the occurrence of birds in agricultural mosaics. The extent of cover of element types, particularly native vegetation, had the strongest influence on all measures of bird occurrence in mosaics. Thus, native vegetation is vital for the persistence of birds in farmland landscapes and is the primary element on which conservation efforts in these environments depend. Nevertheless, with careful management, countryside elements may provide additional conservation benefits for many bird species. Countryside elements made an important contribution to landscape heterogeneity, the landscape property with greatest influence on overall bird richness in mosaics. Countryside elements also increased the structural complexity of cleared agricultural land, and so have the capacity to enhance connectivity in fragmented landscapes. A focus on these factors (landscape heterogeneity and structural complexity) will provide the greatest opportunities for using countryside elements to increase the conservation value of farmland environments for native fauna. The relatively small scale of this study indicates that the cumulative effect of even small elements in farm mosaics contributes to the structural properties of entire landscapes. Critically, this emphasises the important contribution that individual landholders can make to nature conservation in agricultural environments.
2
Sharma, B. Anil Kumar. „Changing agricultural pattern and its impact on land use in south district of Sikkim“. Thesis, University of North Bengal, 2008. http://hdl.handle.net/123456789/1205.
Der volle Inhalt der Quelle
3
Camargo, Marcel Pinton de. „Aerial machine vision, geographical information system and hue for pattern classification in agriculture“. Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/11/11152/tde-17012019-180101/.
Der volle Inhalt der QuelleAnnotation:
In this research we aim to achieve cybernetic cohesion information flow in precision agriculture, integrating machine learning methods, computer vision, geographical information system and UAV-photogrammetry in an irrigated area with slaughterhouse wastewater, under five treatments (W100 - irrigation with superficial water and 100% of nitrogen mineral fertilization, E0, E33, E66 and E100 - irrigation with treated effluent from slaughterhouse and addition of 0, 33, 66 and 100% of nitrogen mineral fertilization, respectively) and four replications on grassland (Cynodon dactylon (L.) Pers.). Several images (between one hundred and two hundred) with red, green, blue (RGB) color model were captured using a quadcopter flying at 20 meter altitude and obtaining spatial resolution of 1 centimeter on a surface of approximately 0.5 ha. The images were orthorectified together with nine ground control points done by differential global positioning system (GPS), both processed in the Agisoft PhotoScan software. Thirteen photogrammetric projects were done over time with 30-day revisit, the root mean squared error (RMSE) was used as accuracy measurement, and reached values lower than 5 centimeters for x, y and z axis. The orthoimage obtained with unmanned aerial vehicle (UAV) photogrammetry was changed from RGB to hue, saturation, value (HSV) color model, and the hue color space was chosen due to independence of illumination, beyond it has a good description of exposure of soil and vegetation, but it is dependent of light source temperature, so difficult to estabilish a static threshold, so we selected an unsupervised classification method, K-Means, to classify the unknown patterns along the area. Polygons were drawn delimiting the area represented by each portion and a supervised classification method based on entropy was used, the decision tree, to explore and find patterns that recognize each treatment. These steps are also displayed in forms of georeferenced thematic maps and were executed in the open source softwares Python, QGIS and Weka. The rules defined on the hue color space reached an accuracy of 100% on the training set, and provided a better understanding about the distribution of soil and vegetation on the parcels. This methodology shows a great potential for analysis of spectral data in precision agriculture.Nesta pesquisa pretendemos alcançar a coesão cibernética no fluxo de informações dentro da agricultura de precisão, integrando métodos de aprendizagem de máquinas, visão computacional, sistema de informação geográfica e aerofotogrametria em uma área irrigada com efluente de matadouro, sob cinco tratamentos (W100 - irrigação com água superficial e 100 % de adubação mineral nitrogenada, E0, E33, E66 e E100 - irrigação com efluente tratado de abatedouro e adição de 0, 33, 66 e 100% de adubação mineral nitrogenada, respectivamente) e quatro repetições em pastagem (Cynodon dactylon (L.) Pers.) Várias imagens (entre cem e duzentas) com modelo de cor vermelho, verde e azul (RGB) foram capturadas por um quadricóptero voando a 20 metros de altitude, e obtendo resolução espacial de 1 centímetro em uma superfície de aproximadamente 0.5 ha. As imagens foram ortorretificadas juntamente com nove pontos de controle, realizados pelo sistema de posicionamento global diferencial (GPS), ambos processados no software Agisoft PhotoScan. Treze projetos fotogramétricos foram realizados ao longo do tempo com revisita de 30 dias, a raiz do erro quadrático médio (RMSE) foi usada como medida de acurácia e atingiu valores menores que 5 centímetros para os eixos x, y e z. A ortoimagem obtida com a fotogrametria do veículo aéreo não tripulado (UAV) foi alterada de RGB para matiz, saturação, valor (HSV) e o espaço de cor matiz foi escolhido devido a independência da iluminação, além de ter boa descrição da exposição do solo e vegetação. Entretanto este é dependente da temperatura da fonte de luz, portanto difícil de se estabelecer um limiar estático, logo selecionamos um método de classificação não supervisionado, o K-Means, para classificar os padrões desconhecidos ao longo da área. Polígonos foram traçados delimitando a área representada por cada parcela e um método supervisionado de classificação baseado na entropia foi utilizado, a árvore de decisão, para explorar e encontrar padrões que reconheçam cada tratamento. Essas etapas também são exibidas em formas de mapas temáticos georeferenciados e foram executadas nos softwares de código aberto Python, QGIS e Weka. As regras definidas no espaço de cor matiz atingiram uma acurácia de 100% no conjunto de treinamento e proporcionaram um melhor entendimento sobre a distribuição do solo e da vegetação nas parcelas. Esta metodologia mostra um grande potencial para análise de dados na agricultura de precisão.
4
Singha, Chandana. „Spatio-temporal change of agricultural land use pattern in Siliguri subdivision, Darjeeling District: Geographical analysis“. Thesis, University of North Bengal, 2018. http://ir.nbu.ac.in/handle/123456789/2784.
Der volle Inhalt der Quelle
5
Okay, Atiye Zeynep. „Spatial pattern and temporal dynamics of northern bobwhite abundance and agricultural landuse, and potential casual factors“. Texas A&M University, 2004. http://hdl.handle.net/1969.1/3355.
Der volle Inhalt der QuelleAnnotation:
There was a long-term decline in northern bobwhite (Colinus virginianus, NBW)
abundance since the 1920s, based on the Christmas Bird Count (CBC) data, but with
substantial spatial and temporal variations across its range. There were four
recognizable periods in the spatial and temporal dynamics of NBW abundance between
1920 and 1990. Severe weather conditions and habitat loss due to land use change
appeared to be the most important factors influencing the long-term trends and spatial
patterns in NBW abundance.
A spatial database of agricultural land use was developed based on the Census of
Agriculture to evaluate the spatial patterns of land use variables over NBW range from
1920 to 1997. The results showed dramatic changes in land use over the period and the
influence of socio-economic events, natural disasters and federal agricultural policies on
the dynamics of land use pattern, and potential implications to NBW abundance were
identified. Replacement of less intensive agriculture with intensive monoculture
production and mechanization coincided with World War I, and the post-war collapse in
agriculture and the economy, partly associated with the Dust Bowl, enhanced this trend.
Monoculture production and clean farming practices were further intensified during
World War II and the years following the war. These land use changes had overall
negative effects on NBW habitat.
Analysis of the changes in spatial pattern of NBW abundance in the Great Plains
region during the severe drought of the 1950s showed a significant decline in NBW
abundance during the drought and a contraction of the NBW range at its western edge.
The post-drought recovery exhibited spatial patterns significantly different from the predrought
ones. These findings suggested that severe drought caused short-term changes
in regional distribution of NBW and range contraction, as well as long-lasting, largescale
changes in spatial distribution of NBW abundance.
This study provides scientific basis for landscape planning and management.
Evaluating the spatial pattern and temporal dynamics of certain wildlife species at large
scales over long-term periods, and identifying potential causal factors are key strategies
for implementing innovative and sustainable approaches to planning and policy. Such
strategies will have a significant impact on future landscape and wildlife species.
6
Pan, Jingwen. „A Study on Agriculture Landscape Application and Development Pattern in Rural Cluj Region“. University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1522340951754843.
Der volle Inhalt der Quelle
7
Nguyen, Thanh Le Vi. „Local Binary Pattern based algorithms for the discrimination and detection of crops and weeds with similar morphologies“. Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2020. https://ro.ecu.edu.au/theses/2359.
Der volle Inhalt der QuelleAnnotation:
In cultivated agricultural fields, weeds are unwanted species that compete with the crop plants for nutrients, water, sunlight and soil, thus constraining their growth. Applying new real-time weed detection and spraying technologies to agriculture would enhance current farming practices, leading to higher crop yields and lower production costs. Various weed detection methods have been developed for Site-Specific Weed Management (SSWM) aimed at maximising the crop yield through efficient control of weeds. Blanket application of herbicide chemicals is currently the most popular weed eradication practice in weed management and weed invasion. However, the excessive use of herbicides has a detrimental impact on the human health, economy and environment. Before weeds are resistant to herbicides and respond better to weed control strategies, it is necessary to control them in the fallow, pre-sowing, early post-emergent and in pasture phases. Moreover, the development of herbicide resistance in weeds is the driving force for inventing precision and automation weed treatments. Various weed detection techniques have been developed to identify weed species in crop fields, aimed at improving the crop quality, reducing herbicide and water usage and minimising environmental impacts.
In this thesis, Local Binary Pattern (LBP)-based algorithms are developed and tested experimentally, which are based on extracting dominant plant features from camera images to precisely detecting weeds from crops in real time. Based on the efficient computation and robustness of the first LBP method, an improved LBP-based method is developed based on using three different LBP operators for plant feature extraction in conjunction with a Support Vector Machine (SVM) method for multiclass plant classification. A 24,000-image dataset, collected using a testing facility under simulated field conditions (Testbed system), is used for algorithm training, validation and testing. The dataset, which is published online under the name “bccr-segset”, consists of four subclasses: background, Canola (Brassica napus), Corn (Zea mays), and Wild radish (Raphanus raphanistrum). In addition, the dataset comprises plant images collected at four crop growth stages, for each subclass. The computer-controlled Testbed is designed to rapidly label plant images and generate the “bccr-segset” dataset. Experimental results show that the classification accuracy of the improved LBP-based algorithm is 91.85%, for the four classes.
Due to the similarity of the morphologies of the canola (crop) and wild radish (weed) leaves, the conventional LBP-based method has limited ability to discriminate broadleaf crops from weeds. To overcome this limitation and complex field conditions (illumination variation, poses, viewpoints, and occlusions), a novel LBP-based method (denoted k-FLBPCM) is developed to enhance the classification accuracy of crops and weeds with similar morphologies. Our contributions include (i) the use of opening and closing morphological operators in pre-processing of plant images, (ii) the development of the k-FLBPCM method by combining two methods, namely, the filtered local binary pattern (LBP) method and the contour-based masking method with a coefficient k, and (iii) the optimal use of SVM with the radial basis function (RBF) kernel to precisely identify broadleaf plants based on their distinctive features. The high performance of this k-FLBPCM method is demonstrated by experimentally attaining up to 98.63% classification accuracy at four different growth stages for all classes of the “bccr-segset” dataset.
To evaluate performance of the k-FLBPCM algorithm in real-time, a comparison analysis between our novel method (k-FLBPCM) and deep convolutional neural networks (DCNNs) is conducted on morphologically similar crops and weeds. Various DCNN models, namely VGG-16, VGG-19, ResNet50 and InceptionV3, are optimised, by fine-tuning their hyper-parameters, and tested. Based on the experimental results on the “bccr-segset” dataset collected from the laboratory and the “fieldtrip_can_weeds” dataset collected from the field under practical environments, the classification accuracies of the DCNN models and the k-FLBPCM method are almost similar. Another experiment is conducted by training the algorithms with plant images obtained at mature stages and testing them at early stages. In this case, the new k-FLBPCM method outperformed the state-of-the-art CNN models in identifying small leaf shapes of canola-radish (crop-weed) at early growth stages, with an order of magnitude lower error rates in comparison with DCNN models. Furthermore, the execution time of the k-FLBPCM method during the training and test phases was faster than the DCNN counterparts, with an identification time difference of approximately 0.224ms per image for the laboratory dataset and 0.346ms per image for the field dataset. These results demonstrate the ability of the k-FLBPCM method to rapidly detect weeds from crops of similar appearance in real time with less data, and generalize to different size plants better than the CNN-based methods.
8
Daggupati, Naga Prasad. „Assessment of the varitarget nozzle for variable rate application of liquid crop protection products“. Thesis, Manhattan, Kan. : Kansas State University, 2007. http://hdl.handle.net/2097/414.
Der volle Inhalt der Quelle
9
Hallstrom, Daniel George. „Agricultural development patterns“. Thesis, Montana State University, 1995. http://etd.lib.montana.edu/etd/1995/hallstrom/HallstromD1995.pdf.
Der volle Inhalt der QuelleAnnotation:
A two-sector general equilibrium model of economic growth has been developed in conjunction with a political economy model of agricultural pricing policies. These theoretical models were used to both present arguments regarding the impact of economic and political forces on agriculture's share of GDP, as well as to provide guides towards specifying the econometric models. Empirical analysis was performed using two data sets. The first covered 81 countries for the years 1971-1981, but contained no explicit measure of policy. The second covered 22 countries for the years 1985-1989, and contained an explicit policy measure in the form of producer subsidy equivalents. Due to the lack of a policy measure in the large data set, a reduced form equation for agriculture's share had to be solved for in order to yield an operational statistical model. Results from this model indicated that variations in agriculture's share could be explained by: level of development, world prices, natural resources, and the political economy variables. For the smaller data set, agriculture's share and producer subsidy equivalents were considered to be jointly endogenous, and so were estimated as a system. It was found that agriculture's share has a negative effect on producer subsidy equivalents, however, producer subsidy equivalents did not have a statistically significant effect on agriculture's share.
10
Ducarouge, Benjamin. „Régulation des systèmes d'adhérence cellulaire par le CRF2 : un effecteur du stress dans le tube digestif“. Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00767103.
Der volle Inhalt der QuelleAnnotation:
Le stress est impliqué dans le développement et l'exacerbation de diverses pathologies notamment au niveau intestinal. Les effets du stress dépendent de l'expression de neuromédiateurs spécifiques (CRF) et de leurs récepteurs. Notre étude porte sur la régulation et la fonction du CRF2 au niveau des entérocytes et des cellules tumorales coliques humaines. In vivo, nous avons montré que le stress et l'inflammation conduisent à l'augmentation de l'expression du CRF2 dans les colonocytes chez le rat. Dans les tumeurs, l'expression du CRF2 augmente avec le grade tumoral. In vitro, dans les cellules HT-29, l'activation du CRF2 induit une altération des jonctions adhérentes et des adhérences focales par la voie Src/ERK/FAK. Ces mécanismes sont responsables de la régulation de la perméabilité épithéliale et de l'augmentation de la migration des cellules tumorales. Ces travaux contribuent à la compréhension des mécanismes impliquant le stress dans le développement des pathologies intestinales.
11
Momsen, Eric. „Vector-Vector Patterns for Agricultural Data“. Thesis, North Dakota State University, 2013. https://hdl.handle.net/10365/27040.
Der volle Inhalt der QuelleAnnotation:
Agriculture is increasingly driven by massive data, and some challenges are not covered by existing statistics, machine learning, or data mining techniques. Many crops are characterized not only by yield but also by quality measures, such as sugar content and sugar lost to molasses for sugarbeets. The set of features furthermore contains time series data, such as rainfall and periodic satellite imagery. This study examines the problem of identifying relationships in a complex data set, in which there are vectors (multiple attributes) for both the explanatory and response conditions. This problem can be characterized as a vector-vector pattern mining problem. The proposed algorithm uses one of the vector representations to determine the neighbors of a randomly picked instance, and then tests the randomness of that subset within the other vector representation. Compared to conventional approaches, the vector-vector algorithm shows better performance for distinguishing existing relationships.National Science Foundation Partnerships for Innovation program Grant No. 1114363
12
Antunes, João Francisco Gonçalves 1965. „Classificação de séries temporais de dados MODIS baseada em redes neuro-fuzzy para o monitoramento sistemático do cultivo da cana-de-açúcar“. [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/257121.
Der volle Inhalt der QuelleAnnotation:
Orientadores: Rubens Augusto Camargo Lamparelli, Luiz Henrique Antunes RodriguesTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola
Made available in DSpace on 2018-08-25T22:49:02Z (GMT). No. of bitstreams: 1 Antunes_JoaoFranciscoGoncalves_D.pdf: 43454007 bytes, checksum: 67ed252d3dc3cb63f6c8b6e62263af20 (MD5) Previous issue date: 2014
Resumo: O setor agrícola brasileiro está sendo marcado por um novo ciclo de expansão do cultivo da cana-de-açúcar. O Brasil é hoje o maior produtor de cana-de-açúcar do mundo, sendo o Estado de São Paulo o maior produtor nacional, com grandes áreas de plantio. Nesse sentido, a estimativa confiável de área plantada da cana-de-açúcar é de fundamental importância para o agronegócio sucroalcooleiro. As geotecnologias têm sido empregadas nas estimativas de safras agrícolas para diminuir o nível de subjetividade dos métodos tradicionais. As imagens do sensor MODIS fornecem uma ampla cobertura da superfície da Terra com alta periodicidade, que possibilitam o monitoramento agrícola sistemático. Entretanto, a sua moderada resolução espacial faz com que possa ocorrer a mistura espectral de diferentes classes de cobertura do solo dentro de um mesmo pixel, acarretando problemas de acurácia na obtenção de estimativas de área. Nesse contexto, o objetivo principal do trabalho foi desenvolver uma metodologia de classificação automática baseada em redes neuro-fuzzy utilizando séries temporais de índices de vegetação MODIS, para estimar a área plantada de cana-de-açúcar no nível sub-pixel. Considerando as safras 2004/2005 a 2011/2012 analisadas no Estado de São Paulo, os mapeamentos gerados pelo modelo de classificação Fuzzy ARTMAP obtiveram uma alta exatidão e baixa discordância, aliado a uma forte correlação linear com as proporções de cana-de-açúcar de referência. Com isso, foi possível obter a estimativa de área plantada no final de março, com antecedência em relação à colheita, ao contrário dos levantamentos oficiais que se estendem até o final da safra, além de utilizarem dados subjetivos. As estimativas de área plantada de cana-de-açúcar baseadas nas Medidas de Compromisso do classificador Fuzzy ARTMAP mostraram-se fortemente correlacionadas e em concordância com as estimativas de área de referência do Canasat, também bem balizadas com as estimativas oficiais do IBGE, em nível municipal, sendo um indicativo de boa precisão. O nível dos desvios entre as estimativas de área mostrou uma variação média municipal menor em relação aos dados do Canasat do que os dados do IBGE. O desempenho do classificador Fuzzy ARTMAP está intrinsecamente relacionado à caracterização da distribuição geográfica do cultivo da cana-de-açúcar nas mesorregiões do Estado de São Paulo, alcançando melhores ajustes onde o cultivo é mais expressivo. Na consolidação para o nível de mesorregiões, os ajustes alcançaram um desempenho ainda superior, indicado por valores extremamente altos de correlação e concordância. Na comparação da área plantada com os dados do Zoneamento Agroecológico da cana-de-açúcar ao longo das oito safras, observou-se que a expansão do cultivo da cana-de-açúcar predomina essencialmente em regiões aptas, com a tendência recente de incorporar mais áreas para produção agrícola do que pastagens. A metodologia de estimativa de área plantada baseada nas Medidas de Compromisso do classificador Fuzzy ARTMAP foi eficiente para o mapeamento da cana-de-açúcar, demostrando grande potencial para a análise sub-pixel de séries temporais de índices de vegetação MODIS
Abstract: The Brazilian agricultural sector has been marked by a new cycle of expansion of sugarcane cultivation. Currently, Brazil is the largest sugarcane producer and the São Paulo State is the largest national producer, with an extensive cropping area. In this sense, a reliable estimation of sugarcane crop area is essential for the sugar-ethanol agribusiness. Geotechnologies have been employed on agricultural crop estimates to reduce the level of subjectivity of the traditional methodologies. MODIS sensor images provide a wide coverage of the Earth¿s surface with high periodicity, supporting the systematic agricultural monitoring. However, its moderate spatial resolution leads to the spectral mixture of different land cover classes within the same pixel, causing accuracy problems on crop area estimation. In this context, the main objective of the study was to develop an automatic classification methodology based on neuro-fuzzy networks using MODIS vegetation indices time-series to estimate the sugarcane crop areas at sub-pixel level. Considering the analyzed cropping years in the São Paulo State, from 2004/2005 to 2011/2012, the maps generated by the Fuzzy ARTMAP classification model showed high accuracy and low disagreement, in addition to a strong linear correlation with the proportions of the sugarcane reference. Then, it was possible to obtain the crop area estimation at the end of March, prior to the harvest period, unlike the official surveys, which extend until the end of the harvest and use subjective data. The sugarcane crop area estimation based on the Commitment Measures from the Fuzzy ARTMAP classifier showed to be strongly correlated and in agreement with the reference area estimation of Canasat, also well marked out with the official estimation from IBGE, at municipal level, being an indicative of good accuracy. The deviation level between the estimations showed a lower municipal average variation in relation to Canasat data than IBGE data. The performance of the Fuzzy ARTMAP classifier is intrinsically related to the characterization of geographical distribution of the sugarcane cultivation in the mesoregions of the São Paulo State, reaching best adjustments where the cultivation is more expressive. In the data consolidation at the mesoregion level, the adjustments achieved even greater performance, demonstrated by extremely high values of correlation and agreement. Comparing the crop area estimation with the Sugarcane Agroecological Zoning in the eight crop seasons, it was observed that this cultivation predominates mostly in suitable regions, with the recent trend of incorporating more areas for agricultural production than pastures. The methodology for crop area estimation, based on the Commitment Measures of the Fuzzy ARTMAP classifier, was efficient for sugarcane crop area mapping, showing great potential for the sub-pixel analysis of MODIS time-series of vegetation indices
Doutorado
Planejamento e Desenvolvimento Rural Sustentável
Doutor em Engenharia Agrícola
13
Cochran, Jason. „Patterns of sustainable agriculture adoptionnon-adoption in Panamá“. Thesis, McGill University, 2003. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=80240.
Der volle Inhalt der QuelleAnnotation:
The promoter system of agriculture extension has been widely studied and accepted as a tool for agriculture development where local resources are scarce. Much development work has been done in Panama using the promoter model. In order to ascertain the local success of this model, promoters trained by World Vision were visited. The adoption of sustainable agriculture practices were measured in five communities where 7 promoters were trained and placed in Veraguas, Panama. Despite the long-term presence of World Vision and trained promoters, only six farmers have adopted at least one sustainable agriculture technique as a result of these extension efforts. Low adoption rates do not necessarily indicate project failure, but does indicate several barriers. These barriers are explored as well as reasons farmers gave for land use. Reasons for S/A use are also explored. Finally, recommendations for improving extension methods and future research are made.
14
Spekken, Mark. „Creating optimized machine working patterns on agricultural fields“. Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/11/11152/tde-22092015-112051/.
Der volle Inhalt der QuelleAnnotation:
In the current agricultural context, agricultural machine unproductivity on fields and their impacts on soil along pathways are unavoidable. These machines have direct and indirect costs associated to their work in field, with non-productive time spent in manoeuvres when these are reaching field borders; likewise, there is a double application of product when machines are covering headlands while adding farm inputs. Both issues aggravate under irregular field geometry. Moreover, unproductive time can also appear in operations of loading/offloading the machine\'s reservoir with inputs/harvested-goods, which can increase with an improper use of the reservoir due to the inadequate machine path length. On the other hand, irregular steep surfaces present a problem for establishment of row crops and machine paths towards erosion. Though contouring (i.e., performing field operations perpendicular to slope direction) is a common practice to reduce runoff and increase water infiltration, still elevation contours are never parallel, while machine operations always are. Many of these issues were target for optimization in computer path planning for agricultural machines, where unproductivity was overall minimized and attempts of soil loss reduction by more proper path establishment also yielded results. This thesis gathered these issues in a combined path planning approach making possible to address soil loss and unproductive costs to their proper location. A number of methods was proposed and modified: creating and replicating steerable machine track; finding more optimal references for path coverage on irregular surfaces (curved or straight); quantifying the impacts of soil loss for a given path pattern; identifying spatially the water flow and concentration; defining geometrically different manoeuvre types and calculate its time, space and energy demands; obtain the overlapped area of input application; and quantifying the machine replenishment cost in relation to underuse of its reservoir for following tracks of inadequate length. An algorithm-application was achieved, which is capable of simulating a large number of path coverage scenarios and to display optimized ones based on a user defined criteria. Sugarcane crop, grown in Brazilian conditions, was the main object of study in this thesis because of its high in-field mechanization costs (along with unproductive operational costs), high susceptibility of soil erosion in its planting phase, and for occupying an area of predominant rolling surface. Case studies were subject to this algorithm that provided suitable outputs with minimized impacts. The outputs of the algorithm were comprehensive and showed potential for the methods to be used by agricultural decision makers.No contexto agrícola atual, improdutividade de máquinas agrícolas em campo e seus impactos sobre o solo ao longo de suas vias são inevitáveis. Estas máquinas têm custos diretos e indiretos associados ao seu trabalho no campo, como tempo improdutivo gasto em manobras quando estes atingem os limites do talhão. Também nestes limites, há uma dupla aplicação de insumos agrícolas quando as máquinas estão cobrindo cabeceiras. Ambas as questões se agravam em talhões de geometria irregular. Além disso, o tempo improdutivo também pode aparecer em operações de carga / descarga do reservatório da máquina com insumos / bens colhidos, o que pode aumentar com um uso indevido do reservatório da máquina devido ao comprimento inadequado do percurso em campo. Ainda, superfícies irregulares e íngremes apresentam um problema para o estabelecimento de culturas em fileira e caminhos de máquinas contra declive. Apesar de operações em nível serem uma prática comum para reduzir o escoamento e aumentar a infiltração de água, curvas de nível nunca são paralelas, enquanto operações agrícolas são sempre paralelas. Muitas destas questões foram alvo de otimização computacional para planejamento de percursos de para máquinas agrícolas, onde a ineficiência foi, em geral, minimizada e tentativas de redução da perda de solo estabelecimento de percursos mais adequados também produziu resultados. Esta tese reuniu estas questões em uma abordagem de planejamento de percurso quantificando e direcionando custos de perda de solo e improdutividade de máquinas para sua devida localização. Métodos foram propostos e modificados, como: criar e replicar trajetos transitáveis de máquinas; encontrar referências ideais para a cobertura do trajeto em superfícies irregulares (curvas ou retas); quantificação dos impactos da perda de solo por um determinado padrão de percursos; identificar espacialmente o fluxo da água e sua concentração; definir geometricamente diferentes tipos de manobras e calcular o seu tempo, espaço e energia demandada; obter a área sobreposta de aplicação de insumos; e quantificar custo de reposição da máquina em relação à subutilização de seu reservatório para seguir trajetos de comprimento inadequado. Um aplicativo-algoritmo foi obtido capaz de simular um grande número de cenários de padrões de percurso, e exibindo aqueles que foram otimizados por critérios definidos pelo usuário. A cultura da cana, em condições brasileiras, foi a principal cultura de estudo nesta tese devido ao seu alto custo de mecanização (assim como custos operacionais improdutivos), alta suscetibilidade à erosão do solo na sua fase de plantio, e ocupando predominantemente áreas de superfície irregular. Os estudos de caso foram sujeitos ao algoritmo que obteve resultados coerentes e impactos minimizados. Os resultados do algoritmo mostram potencial para que os métodos avaliados sejam utilizados por tomadores de decisão da área agrícola.
15
Taniguchi, Kiyoshi. „Three essays on Japanese consumption patterns and agricultural policy“. Connect to resource, 2001. http://rave.ohiolink.edu/etdc/view.cgi?acc%5Fnum=osu1261312378.
Der volle Inhalt der Quelle
16
Estel, Stephan. „Mapping patterns of agricultural land-use intensity across Europe“. Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät, 2016. http://dx.doi.org/10.18452/17583.
Der volle Inhalt der QuelleAnnotation:
Die weltweite Bevölkerungszunahme, sich ändernde Ernährungsgewohnheiten, und die Nachfrage nach Bioenergie erfordern eine Erhöhung der landwirtschaftlichen Produktion. Die Intensivierung bestehender landwirtschaftlicher Flächen ist hierbei eine mögliche Option. Allerdings verstehen wir nur wenig von den räumlichen Mustern der landwirtschaftlichen Nutzungsintensität, da adäquate Datensätze fehlen. Europa ist eine beispielhafte Region, in der eine Intensivierung als auch ein Rückgang der Landnutzung stattfindet. Ziel dieser Dissertation war es Methoden zu entwickeln, die MODIS NDVI Zeitreihen und statistische Daten kombinieren und eine europaweite Kartierung der landwirtschaftlichen Nutzungsintensität ermöglichen. Für eine Einschätzung der landwirtschaftlichen Nutzungsintensität wurden eine Reihe von Intensitätsindikatoren entwickelt und kartiert. Die resultierenden Karten zeigen eine hohe Landnutzungsintensität in West- und Zentraleuropa und dem Mittelmeerraum, gekennzeichnet durch Mehrfachernten und langen Anbauzeiten. Gebiete mit niedriger Intensität lagen in Osteuropa, in Gebirgsregionen sowie in der Extremadura in Spanien, wo Brachland und die Aufgabe von Agrarflächen häufig sind. Die Aufgabe von Agrarflächen ist ein aktueller Prozess der Landnutzungsveränderung in Osteuropa, während die gleichzeitige Rekultivierung ehemaliger Agrarflächen ebenfalls umfassend ist. Diese räumlichen Muster lassen sich mit unterschiedlichen Agrarumweltbedingungen begründen aber auch mit sozioökonomischen Veränderungen wie die Restrukturierung des osteuropäischen Agrarsektors nach 1989 oder die Marginalisierung landwirtschaftlicher Flächen insbesondere in Gebirgsregionen. Die entstandenen Karten belegen das Potential von MODIS NDVI Zeitreihen, komplexe Phänomene landwirtschaftlicher Nutzungsintensität zu erfassen. Diese könnten genutzt werden um Umweltfolgen der landwirtschaftlichen Produktion zu bewerten oder Zielregionen für eine nachhaltige Intensivierung zu identifizieren.Global population growth, changing diets, and the demand of bioenergy require an increase in agricultural production. Intensifying agricultural production is one pathway to meet increasing demands. However, our understanding of spatial patterns of agricultural land use remains weak since adequate data sets are lacking. Europe is as a prime example for a region that is undergoing both, intensification as well as decreasing agricultural land use. The goal of this doctoral thesis was to develop methodologies that combine MODIS NDVI time series and agricultural statistics to map spatial patterns of land-use intensity across Europe. To assess land-use intensity, a wide range of intensity indicators were mapped. The resulting maps revealed high-intensity areas in Western and Central Europe and the Mediterranean region, characterized by multi-harvests and long crop duration. Low-intensity areas are mostly located in Eastern Europe, in mountain regions and the Extremadura in Spain, where fallow and abandonment land are widespread. Agricultural abandonment is an ongoing land-use change process in Eastern Europe. At the same time, recultivation of formerly abandoned land is widespread as well. These spatial patterns are the result of agro-environmental conditions but also of changes in socio-economic conditions such as the restructuring of the agricultural sector in eastern European countries after 1989, or the marginalization of farmland especially in mountain regions. The resulting maps show the potential of MODIS time series to assess the complex phenomenon of land-use intensity. They may form a basis to assess the environmental outcomes of agricultural production and to identify target regions for sustainable intensification.
17
Andersen, Matthew Alan. „Pro-cyclical productivity patterns in U.S. agriculture /“. For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2005. http://uclibs.org/PID/11984.
Der volle Inhalt der Quelle
18
Brown, Paul W., Teles Machibya und Bruce Russell. „Wind Flow Patterns at the University of Arizona Agricultural Centers“. College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/310802.
Der volle Inhalt der Quelle
19
Clark, Matthew Ken. „Effects of high commodity prices on western Kansas crop patterns and the Ogallala aquifer“. Thesis, Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/1136.
Der volle Inhalt der Quelle
20
Pele, Winnie Kasoma. „Income and bean consumption patterns in Zambia“. Thesis, Kansas State University, 2015. http://hdl.handle.net/2097/19751.
Der volle Inhalt der QuelleAnnotation:
Master of AgribusinessDepartment of Agricultural Economics
Vincent Amanor-Boadu
The literature shows that increases in incomes lead to changes in the allocation of income or expenditure shares to different food products. The purpose of this thesis is to identify the effect of income on expenditure share allocations among different food groups. The study was particularly interested in beans and how changes in incomes affect the share of bean expenditures. We used data from the 2010 Zambia Living Conditions Monitoring Survey (LCMS). The LCMS covers the whole country and provides segmentation of the respondents, across the region and rural versus urban. It also provides detailed information on the income and expenditure distributions of respondent households. This allowed for the achievement of the overall objective of this thesis: understanding how beans and other food products responded to income changes as well as other demographic and socio-economic variables. The food share is the proportion of total household income that was allocated to food. The results show that food averages about 40% of income but varied significantly across the four income groups. It was 92% for those earning less than ZMW300 per month and 37% for those earning between ZMW300 and ZMW750 per month. It was down to 22.6% for those earning between ZMW750 and ZMW2.1 million per month had a food share of total income of only 10.8%, similar to the average U.S. consumer. These averages were found to be statistically different across the income groups. We found that Zambians allocated about 40% of their food expenditure to cereals compared to 5% to pulses and 3.5% to beans. They allocated a higher proportion of their food expenditure to fruits and vegetables than to beans and/or to pulses. This shows that legumes are very low on the food hierarchy in Zambia. However, across income categories, it was found that consumers in the second income group (ZMW300 and ZMW750 per month) allocated the most of their food expenditure to beans, about 3.9%, while those in the highest income group (ZMW750 and ZMW2.1 million per month ) allocated the least, about 3%. The biggest influencing demographic factor for pulses and beans’ shares of food expenditure was locale, with urban consumers having about 1.1 and 0.8 percentage points higher share of food expenditures allocated to beans than rural consumers. The respective t-values were 15.58 and 16.96. All the demographic and socio-economic variables were statistically significant at or below the 5% level. There was no difference between the allocation of people in the highest income group and those in the lowest income group. The results suggest that if the long-term objective is to reap the nutritional benefits of beans, there may be value in focusing on two principal policy variables: education and income enhancement. However, because education is correlated with income, the benefits of undertaking this policy initiative would more than benefit the bean consumption. It should unleash across the economy a more productive workforce that understands the health benefits of its food choices.
21
Fox, Susan. „A Comparison of Chemical Composition & Fermentation Patterns of Alternative Silages to Whole Plant Corn Silage“. TopSCHOLAR®, 1989. https://digitalcommons.wku.edu/theses/2346.
Der volle Inhalt der QuelleAnnotation:
A comparison of the relationship of fermentation to chemical composition was made for forages which were wilted and ensiled at 35 to 45 percent dry matter. Trial I consisted of three forages ensiled in October, 1981: interseeded soybeans and grain sorghum. whole plant corn with added anhydrous ammonia, and whole plant corn with shelled corn added at a rate of 150 kg/t of fresh forage. Trial II consisted of two forages ensiled in 1982: interseeded soybeans and pearlmillet, and wheat. Temperatures of fermentation were collected, and chemical composition during the first 25 days of fermentation analyzed.
Production data were also collected in Trial I. The cash expenses and yields do not indicate a significant advantage to either crop in this study in terms of yields and return over variables. In terms of plant nutrient content there was an advantage for soybean/grain sorgum silage in protein yield of 854 kilograms per hectare as compared to whole plant corn silage.
Temperature data collected on the forages in Trial I covered 57 days from October 8 through December 4. The maximum recorded temperatures for soybean/grain sorghum, corn silage with added anhydrous ammonia and the corn silage control were 37, 37, and 24 degrees Celcius. achieved by day 11, 4, and 11 of ensilement respectively. The rapid temperature increase for material treated with anhydrous ammonia confirmed previous reports. Small fluctuations occurred in silage temperatures but these were not correlated to ambient temperature. Temperatures declined very slowly in all forages, with the lowest reading for silages by day 57 recorded at 19 C for soybean/grain sorghum silage. Ambient temperature was not reached in the ensiled mass during the 57 day period in which data were recorded.
The soybean/pearlmillet ensiled in Trial II quickly reached a high peak temperature of 44 C at 4 days of ensilement, gradually decreasing over a 57 day period to 35 degrees on October 19. The silage did not reach a desireable pH. Initial forage pH was high, 7.4, dropped rapidly to 5.1 on day 5, but did not decline further in succeeding samples. Samples were low in lactic acid and high in acetic acid content.
Initial buffering capacities for both of the soybean mixture forages were considerably higher than the other forage materials. Buffering capacities at day 0 for whole plant corn, whole plant corn treated with anhydrous ammonia, soybean/grain sorghum, soybean/pearlmillet and wheat forages IA ere 19.4, 20.0, 35.3, 35.3. 38.6 and 22.2 milliequivalents/100 g of dry matter respectively. Increases in buffering capacities during fermentation were smaller for soybean/grain sorgum and soybean/pearlmillet . Buffering capacity increases for the forages were 133.5, 290.5, 69.1, 64.2 and 87.4%.
High ammonia nitrogen levels were found in samples of whole plant corn silage with added anhydrous ammonia obtained on days 10 and 20 of ensilement. These contained .282 and .351% ammonia-nitrogen and tested 18.0 and 20.1% crude protein. The increase in buffering capacity which occurrs with addition of anhydrous ammonia was confirmed by the higher acetic acid and pH levels, with corresponding decreases in lactic acid from samples taken days 10 and 25. Crude protein levels were 17.9 and 17.4 percent while the other samples contained only 10-12% crude protein. It appeared that application of anhydrous ammonia was not uniform throughout the silage. Where high concentrations of ammonia occurred fermentation was prolonged as indicated by excessive amounts of lactic and acetic acids and a high pH in these samples. Values for L(+) lactic acid ranged from .2 to .523 in fresh forage to 5.66% of dry matter on day 25. Concentrations of ammonia-nitrogen in the other silages ranged from .061 to .131%.
The low buffering capacity of whole plant corn silage was reflected by normal concentrations of lactate and acetate but a more acidic pH when compared to the other forages. Lactic and acetic acid production for soybean/grain sorghum silage was similar to that of the corn silage control. Corn silage pH was lower, however, throughout fermentation and reached a stable pH by day 5 of fermentation. The wheat silage went through a gradual fermentation with low lactic acid production, and an intermediary ending pH of 4.0.
Fermentation was essentially complete by day 10 in all silages as indicated by pH, buffering capacity, and lactic acid production: however, there was a tendency for buffering capacity and acetic acid content to increase in all of the ensiled materials throughout the 25 day collection period.
22
Kufimfutu, Bakelana ba. „Crop planting pattern effects on crop and weed growth /“. The Ohio State University, 1992. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487778663287222.
Der volle Inhalt der Quelle
23
Chakraborty, Manas. „Spatial pattern in macroinvertebrate communities in headwater streams of New Zealand and a multivariate river classification system : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Ecology at Massey University, Palmerston North, New Zealand“. Massey University, 2008. http://hdl.handle.net/10179/1067.
Der volle Inhalt der QuelleAnnotation:
Macroinvertebrate data collected from 120 headwater streams in New Zealand were used to test the ability of the Freshwater Environments of New Zealand River Classification (FWENZ) to explain spatial variation in unimpacted stream invertebrate communities. FWENZ is a GIS based multivariate river environment classification of the sections of national river network. The classification performance of the FWENZ was examined to determine the optimum classification level which could be used for the purpose of conservation and biomonitoring of New Zealand rivers and streams. The classification performance of the FWENZ was also compared to those of two other river classification systems, the ecoregions and the River Environment Classification (REC). Results of the analysis of similarity (ANOSIM) test showed that discrimination of the study sites based on interclass differences in macroinvertebrate community composition was optimal at FWENZ 100 class level which classifies the New Zealand rivers and streams into 100 different groups. The FWENZ 100 class level distinguished the biological variation of the study sites at a finer spatial scale than the REC Geology level. Although performance of the ecoregions classification was stronger than both the river environmental classifications, the REC and the FWENZ, but it was unable to explain the variation in local assemblage structures. Multivariate analyses of the macroinvertebrate abundance data and the associated environmental variables at three different spatial scales (upstream catchment, segment, and reach) were used to identify environmental predictors of assemblage patterns. Catchmentscale measures of climatic, topographic and landcover factors were more strongly correlated with macroinvertebrate community structures than segment scale measures, whereas reachscale measures of instream physicochemical factors and riparian characteristics had the least association with assemblage patterns. Despite the strong influences of cathment-scale factors on macroinvertebrate communities, local factors like water temperature, stream velocity, reach elevation, percent canopy cover and percent moss cover were also involved in explaining the within-region variation in assemblage patterns, which indicates the importance of considering regional as well as local factors as surrogates of stream invertebrate communities to provide a base for stream bioassessment programmes at multiple scales.
24
Roy, Ranjan. „Changing pattern in agriculture ; a case study of Koch Behar district“. Thesis, University of North Bengal, 2009. http://hdl.handle.net/123456789/258.
Der volle Inhalt der Quelle
25
Schwoob, Marie-Hélène. „The sociopolitical patterns of agricultural modernization in China : stepping on transition pathways“. Thesis, Paris, Institut d'études politiques, 2015. http://www.theses.fr/2015IEPP0025/document.
Der volle Inhalt der QuelleAnnotation:
Notre recherche, qui prend pour point de départ le récent renouveau de l’intérêt du gouvernement chinois pour le développement agricole, s’appuie sur deux approches. La première se fonde sur une analyse des documents de référence promulguant les lignes directrices des politiques de modernisation agricole entre 2004 et 2014, et a pour but de saisir les traits du référentiel dominant de modernisation tel que promu par le gouvernement central. Ce référentiel dominant, en particulier, promeut deux objectifs principaux – la sécurité alimentaire et le développement économique – et trois outils de mise en œuvre : le développement scientifique et technologique, l’implication des entreprises et l’exode rural. La diffusion de ce référentiel dominant a des conséquences sur les schémas sociologiques de la production agricole, que la deuxième approche explore au sein de quatre régions d’étude situées dans les provinces, zones administrative et municipalité du Ningxia, du Jiangxi, du Shandong et de Pékin. Cette analyse sociologique se penche sur l’étude des modalités de réinvestissement des activités de production agricole par les officiels locaux et montre que ces derniers s’appuient de manière préférentielle sur un réseau d’agroentrepreneurs industriels locaux. L’analyse des structures relationnelles locales qui se forment ou se cristallisent au cours de ce processus permet de saisir les contours de la trajectoire de modernisation sur laquelle s’engage aujourd’hui l’agriculture chinoise et révèle la formation d’obstacles institutionnels et sociologiques à l’évolution des pratiques agricoles vers plus de durabilité sociale et environnementaleThis dissertation takes as its point of departure the recent renewal of the interest of the Chinese state in agricultural development. The approach of this research is twofold: political and sociological. The political approach focuses on the analysis of agricultural modernization policies between 2004 and 2014, with the aim of understanding the frames of reference of agricultural modernization promoted by the central government, which is characterized by two main goals – food security and economic development – and three main levers – science and technology, industries and the rural exodus. The spreading of this dominant frame of reference has effects on the sociological patterns of agricultural production, which are explored by the second approach of this research in four targeted areas: Beijing, Shandong, Jiangxi and Ningxia. Drawing on fieldwork and interviews, this sociological analysis investigates the modalities of the reinvolvement of Chinese government officials in rural areas through the implementation of policies aimed at modernizing agricultural production and examines the pattern of relationships and the roles played by political and economic stakeholders in the modernization process. The analysis of the sociopolitical frames built in the course of the modernization of agricultural production enables to identify the features of the agricultural modernization pathway China is engaging on. In particular, the established patterns of power and institutions in rural areas led to the establishment of roadblocks that impede transition towards social and environmental sustainability of agricultural production
26
Uwannah, Chukwuemeka Emmanuel. „Communication linkage patterns in the agricultural research and extension systems in Nigeria“. Thesis, University of Reading, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298664.
Der volle Inhalt der Quelle
27
Abdullah, Rahman. „The influence of settlement patterns on agricultural productivity in Central Sulawesi Indonesia /“. Göttingen : Cuvillier, 2000. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=009315102&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Der volle Inhalt der Quelle
28
Mandal, Tapash. „Trends and patterns of agricultural hand use in Maldah district, West Bengal“. Thesis, University of North Bengal, 2022. http://ir.nbu.ac.in/handle/123456789/5096.
Der volle Inhalt der Quelle
29
Lyle, Peter J. „Growing food in the city: A study across interaction design and urban agriculture“. Thesis, Queensland University of Technology, 2015. https://eprints.qut.edu.au/84902/29/84902%28thesis%29.pdf.
Der volle Inhalt der QuelleAnnotation:
The thesis offers the foundation of a design pattern language for urban gardening, as well as a prototype mobile storytelling platform through which urban gardeners can share gardening experiences. This study examined three urban agriculture communities – a city farm, a permaculture movement, and residential gardeners – in order to better understand some of the challenges in their food growing practices.
The city is increasingly being rediscovered by gardeners, food activists, and local governments as an under-utilised opportunity space for land cultivation and local food production, and the findings of this research were analysed with a view to consider interactive technology and design interventions in response.
30
Weiland, Andrew W. „Marshelder (Iva annua L.) Seed Morphology and Patterns of Domestication in Eastern North America“. The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1365684474.
Der volle Inhalt der Quelle
31
Hutchins, Richard Kinsley. „Changing patterns of tastes and preferences for food in Great Britain“. Thesis, University of Newcastle Upon Tyne, 1993. http://hdl.handle.net/10443/296.
Der volle Inhalt der QuelleAnnotation:
Recently the importance of underlying, non-economic factors in the determination of food choice has been increasing. It is hypothesised that changes in these underlying factors, sometimes known as food preferences, are a function of fundamental changes in consumers' attitudes. Attitudes, defined as the belief about an object, the emotions associated with it and the readiness to behave in a certain way, can in turn, it is contended, be determined by socio-economic and demographic measures. The precise nature of food preference changes in Great Britain is measured, and it is shown that post hoc variables are better than a-priori variables at segmenting consumers with respect to their consumption of foods. Moreover, these post hoc variables are statistically significant determinants of the consumption of those foods which have undergone the most marked preference changes in recent years.
32
Lindquist, Thérese. „Undersökning av mängden organiskt kol i ett område med sura sulfatjordar i Kristianstads kommun“. Thesis, Linnéuniversitetet, Institutionen för biologi och miljö (BOM), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-89373.
Der volle Inhalt der QuelleAnnotation:
I Fredriksdalsvikens naturreservat i Kristianstads kommun skedde omfattande metalläckage efter en översvämning sommaren 2007 som orsakade skador på djur- och växtliv. De kraftiga metalläckagen misstänks härledas till sura sulfatjordar. Sura sulfatjordar tillhör de miljöskadligaste jordarna i världen på grund av de kraftiga metalläckagen och försurningen som jordarna orsakar till omgivningen. Mot bakgrund till humusämnens centrala roll för metalltransport i naturliga miljöer, syftade denna studie till att kartlägga hur organiskt kol är fördelat, sprids samt hur det kan förklaras i ett område nära det drabbade naturreservatet. Studien är en del av ett pågående forskningsprojekt i området som bedrivs på Linnéuniversitetet. I studiens undersökningsområde dominerar jordbruksmark som dräneras av ett dikessystem från norr till söder. Vattnet som avleds i dikessystemet pumpas slutligen till en våtmark i Fredriksdalsvikens naturreservat. I studien analyserades jord från åkermark, dikessediment, porvatten och dikesvatten från området på totalt organiskt kol med metoderna glödförlust och kyvett-test. Totalhalterna jämfördes med pH och grundvattennivå i åkermark. Resultat och slutsatser av studien är att högst halter löst organiskt kol uppmättes i dikesvattnet uppströms i dikessystemet och beror troligtvis på bottenfauna som inte växer i andra delar av systemet. I dikessediment ökar den organiska halten nedströms i dikessystemet och kan förklaras genom tillförsel av organiskt kol från två diken som dränerar åkermark rik på organiskt kol. De högsta halterna organiskt kol i jord beror på ett tunt torvlager. I åkermark visar inte resultaten någon tydlig statistisk korrelation mellan pH och totalt organiskt kol, men kraftig pH-sänkning tillsammans med höga totalhalter organiskt kol i torvjord beror troligtvis snarare på humusämnen än på sur sulfatjord. I åkermark väster om dikessystemet ökar den organiska halten med djupet under grundvattenytan. I samma åkermark ökar halterna av totalt organiskt kol lateralt mot dikessystemet, parallellt med att pH sjunker som troligen påverkas av starkare bindningsmekanismer till mineral, lägre mikrobiell aktivitet och minskad urlakning av löst organiskt kol. Men fler undersökningar i området krävs då markanvändning, erosion, jordarternas textur och sammansättning samt vattnets spridningsvägar också är avgörande faktorer för fördelning och spridning av organiskt kol i naturliga miljöer.In the nature reserve Fredriksdalsviken in Kristianstad municipality, extensive metal leakage occurred after a flood in the summer of 2007 that caused damage to wildlife and plant life. The heavy metal leaks are suspected to be derived from acid sulphate soils in the area. Acid sulphate soils are among the most environmentally harmful soils in the world due to its extensive acidification and leaching of metals to the environment. In the light of humic substances key role for metal transport in natural environments, this study aimed to investigate how organic carbon is distributed, spread and how it can be explained in an area near the affected nature reserve. The study is part of an ongoing research project in the area conducted at Linnaeus University. The study area is dominated by agriculture land which is drained by a ditch system from north to south. The drained water in the ditch system is finally pumped to a wetland in the Fredriksdalsviken nature reserve. In the area, total organic carbon was analysed on soil from arable land, ditch sediment, pore water and ditch water with the methods loss of ignition and cuvette-test. Total levels were compared with pH and the groundwater level in arable land. The results and conclusions of the study are that the highest content of dissolved organic carbon in the ditch water upstream the ditch system is probably due to benthic fauna that doesn’t grow in other parts of the system. In the ditch sediment, the organic content increases downstream in the ditch system and can be explained by the supply of organic carbon from two ditches that drain arable land rich in organic carbon. In arable land are the highest levels of organic carbon due to a thin peat layer. The results does not show a clear statistical correlation between pH and total organic carbon in soil, but a sharp decrease in pH together with high total levels of organic carbon in peat soil is probably due to humic substances rather than to acid sulphate soil. In the western arable land of the ditch system, levels of total organic carbon increase laterally towards the ditch system at the same time as the pH decreases, which is probably affected by stronger binding mechanisms to minerals, lower microbial activity and reduced leaching of dissolved organic carbon. However, more research is required in the study area, since land use, erosion, soil texture and constitution together with the flow paths of water also are crucial factors for the distribution and pathways of organic carbon in natural environments.
33
Gansner, James Hill. „Agricultural development and fertility patterns in the dry zone of Sri Lanka, 1946-1971“. Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25407.
Der volle Inhalt der QuelleAnnotation:
The main objective of this study is to determine whether 1971 fertility differentials in Sri Lanka's dry zone can be explained in terms of agricultural development. It is hypothesized that agricultural development might be associated with low fertility due to the effects of agricultural development on intermediate variables found to be closely related to fertility in other studies. Yotopoulos work on the relation between economic development and fertility provides a useful theoretical frame. The methodology employed is path analysis. Findings indicate that agricultural development is not related to fertility differentials in Sri Lanka's dry zone. Differentials in fertility are explained primarily in terms of cultural factors, female education, female age at marriage, and family planning.Graduate and Postdoctoral Studies
Graduate
34
Nuworsu, Eugene Kwaku Mawutor. „Modeling the Impacts of Changing Agricultural Patterns on Rainfall and Temperature in North Dakota“. Thesis, North Dakota State University, 2020. https://hdl.handle.net/10365/31852.
Der volle Inhalt der QuelleAnnotation:
Global climate change has been an issue of much concern for many years now with human activity being the main contributor to this phenomenon. However, some evidence in the United States Midwest suggests that there has been a decline in summer temperatures and a rise in summer rainfall as a result of increasing agricultural production in this region. This research applies a system of simultaneous equations more specifically a seemingly unrelated Tobit regression model to understand how land-use change and increasing crop production may be contributing to these changes in rainfall and temperature in the months of June, July, August and September in the state of North Dakota. The findings from the study indicate that corn production to some extent is contributing to increasing precipitation and declining temperatures in North Dakota.
35
Osterman, My. „Carbon dioxide in agricultural streams : Magnitude and patterns of an understudied atmospheric carbon source“. Thesis, Uppsala universitet, Luft-, vatten och landskapslära, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-355402.
Der volle Inhalt der QuelleAnnotation:
The role of streams in the global carbon budget was for a long time neglected, since they were considered passive transporters of carbon from land to sea. However, studies have shown that streams are often supersaturated in carbon dioxide (CO2), making them sources of carbon to the atmosphere. The main sources of stream CO2 are in-stream mineralization of organic matter and transport of carbon from the catchment. The catchment derived CO2 could both be of biogenic (respiration) or geogenic (weathering) origin. Most studies regarding the topic rely on measurements carried out in forest-dominated catchments, while agricultural streams are under-represented. The objective of this study was to examine partial pressure of CO2 (pCO2) in streams in catchments dominated by agriculture. This was done to increase the knowledge about agricultural influence on stream pCO2, and to provide a basis for planning mitigation strategies for reducing CO2 emissions from the agriculture sector. Sampling was performed in ten streams draining agriculture-dominated catchments around Uppsala, Sweden, from June to November 2017. Measurements of pCO2 were carried out with floating chambers, equipped with CO2 sensors. Nutrients, organic carbon, discharge and different chemical variables were also measured. For correlation tests, the method Kendall’s Tau was used. Catchments were delineated in a geographic information system (GIS) and the CORINE Land Cover dataset was used to examine land use. Stream specific median pCO2 varied from 3000 to 10 000 μatm. In some streams, pCO2 exceeded 10 000 μatm, which was outside of the sensor’s measurement range. Values of pCO2 were high compared to similar studies in forested catchments, which could indicate that occurrence of agriculture in the catchment increases stream CO2. Correlation was found between pCO2 and discharge, with negative correlation in five streams and positive correlation in two. Negative correlation was found between pCO2 and pH and percentage of dissolved oxygen, respectively. No significant correlation was found between pCO2 and fraction of agricultural land use, nutrients or organic carbon. Further studies are needed to examine the sources of CO2, since it is possible that a large part of the CO2 has a geogenic origin. The floating chamber method should be revised to reduce the sensor’s sensitivity to condensation and cold temperatures, and to increase the measuring range.
36
Farr, C. R. „Planting Patterns Under Drip Irrigation“. College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/219749.
Der volle Inhalt der QuelleAnnotation:
The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers.Planting pattern 2x1 skip row cotton outyielded variable row 32"x44" per gross field acre under drip irrigation with saline water. Skip row planting in deep water areas appears to be a feasible selection with high water cost, reduced tubing requirement, lowered land rentals and increased yield response.
37
Turechek, William W. „Spatial characteristics of Phomopsis Leaf Blight and Leaf Spot of Strawberry : pattern, association, and scale /“. The Ohio State University, 1999. http://rave.ohiolink.edu/etdc/view?acc_num=osu1488190109871094.
Der volle Inhalt der Quelle
38
Stewart, Carlyn Celeste. „Examining Agricultural Prehistoric Land Use Patterns Based on Soil Analysis in Petrified Forest National Park“. Thesis, The University of Arizona, 2015. http://hdl.handle.net/10150/579021.
Der volle Inhalt der QuelleAnnotation:
A geoarchaeological study was conducted at Petrified Forest National Park to investigate prehistoric land use of the area by relating cultural deposits to Holocene environments. The field site may have been used for agriculture. The soil properties of five different micro-environments including a sand dune swale, the edge of a modern wash, a floodplain, a sand dune, and a sloping fan off of a mesa within this area were compared to see what types of prehistoric agricultural methods may have been successful within Petrified Forest and where they were used. Basic field methods included augering and in-field soil analysis of physical properties. The augering resulted in reconstruction of the stratigraphic sequence in the study site. The results concluded that the sediment from the sand dune swale exhibited all the properties necessary to successfully utilize the area for dune agriculture, a common method used by the Ancient Puebloans in arid environments, though other methods and areas were likely used as well.
39
Ahmed, Saleh. „Spatial Patterns of Rural and Exurban Residential Settlement and Agricultural Trends in the Intermountain West“. DigitalCommons@USU, 2015. https://digitalcommons.usu.edu/etd/4230.
Der volle Inhalt der QuelleAnnotation:
In recent years, counties in the Intermountain West (CO, ID, MT, UT, WY) have experienced rapid population growth and housing development, and much of this growth is occurring outside of urban areas. Residental development can have negative impacts on farmlands, farm viability, and environmental services provided by working landscapes. In this study, I use county-level data to explore the association between residential settlement patterns and trends in farm numbers, copland acres, and farm sales between 1997-2012 in this region. Results from traditional ordinary least-squares and spatial regression models demonstrate that population pressure (e.g. rural population density), socioeconomic structure (e.g. median household income), and biophysical resources (e.g. length of growing season) are related to different types of farm trends, but that accounting for the spatial pattern or arrangement of rural and exurban residential development can improve models to explain agricultural change. Since spatial dependencies are present among different variables, this study also demonstrates that spatial regression methods are appropriate and useful to use when modeling country-level processes of socioeconomic change.
40
Stone, Glenn Davis. „Agrarian ecology and settlement patterns: An ethnoarchaeological case study“. Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184498.
Der volle Inhalt der QuelleAnnotation:
Although settlement patterns are a central topic of archaeological research, there is a paucity of general theory on the determinants of agrarian settlement. What passes for a theory of agrarian settlement in archaeology is a borrowed model which does not recognize the relationship between population density and agricultural intensity. This dissertation argues that the rules determining where farmers settle are inextricable from how they farm. Ethnohistoric and ethnoarchaeological data are used to investigate the relationship between agricultural change and the determinants of settlement location in the case of the Kofyar, a population of farmers colonizing a frontier area in the central Nigerian savanna. As they moved into an area with a low ratio of population to productive land, Kofyar agriculture was extensified in accord with the Boserup (1965) model. With potentially greater travel costs associated with domestic water than with farm plots, streams exerted a strong attraction to early settlements. With increasing land pressure, the attraction value of farmland eclipsed the attraction to water. Contrary to Boserup's theory that agricultural responses to land pressure cross-cut environments, analysis of settlement histories of over 1000 households shows that responses vary with soil type. Farmers on high-quality sandstone-derived soils tend to intensify cultivation, while farmers on inferior shale-derived and igneous-derived soils tend to abandon their farms when yields begin to decline. The location of Kofyar compounds with respect to each other is closely related to the labor demands of agricultural production. The restricted range of distances between residential compounds reflects the reliance on inter-household collaboration in agricultural production.
41
Passewitz, Gregory R. „Social Exchange Theory and Volunteer Organizations: Patterns of Participation in Four Environmental/Natural Resource Organizations“. The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu1392653996.
Der volle Inhalt der Quelle
42
Mitchell, Kenneth S. „Turbulence and change in department spending patterns case study: Department of Agriculture“. Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/43733.
Der volle Inhalt der QuelleAnnotation:
Approved for public release; distribution is unlimitedThis thesis examines the relationship between agency assertiveness and moderation of budget requests within the Department of Agriculture. It covers the budgetary roles and strategies used in the DOA, Office of Management and Budget, and Congressional appropriation committees. The database used was supplied by the DOA and contains agency initial budget requests and appropriation data from 1980 to 1990. The analysis compares agency budget request increments to the actual increments appropriated, as a percentage of a common base. The study found that during periods of fiscal restraint, the most assertive agencies were the most successful. However, with the support of clientele groups and legislative branch members, agencies requesting moderate increases as well as decreases experienced significant growth in their funding levels and restoral of budget cuts made earlier.
43
Mitchell, Kenneth S. „Turbulence and change in department spending patterns case study Department of Agriculture /“. Monterey, Calif. : Naval Postgraduate School, 2008. http://handle.dtic.mil/100.2/ADA245057.
Der volle Inhalt der QuelleAnnotation:
Thesis (M.S. in Management)--Naval Postgraduate School, December 2008.Thesis Advisor(s): McCaffery, Jerry L. "June 1991." Description based on title screen as viewed on March 4, 2009. Includes bibliographical references (p. 41). Also available in print.
44
Oelberg, Thomas Jonathan. „Meal patterns and nitrogen metabolism in dairy cows /“. The Ohio State University, 1985. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487259580262914.
Der volle Inhalt der Quelle
45
Watson, J. E. „Water Uptake Pattern by Cotton Roots from a Drip Irrigated Field“. College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/219750.
Der volle Inhalt der Quelle
46
Silvertooth, J. C., P. W. Brown und J. E. Malcuit. „Basic Cotton Crop Development Patterns“. College of Agriculture, University of Arizona (Tucson, AZ), 1991. http://hdl.handle.net/10150/208324.
Der volle Inhalt der QuelleAnnotation:
Summaries of cotton crop phenology, as a function of heat units (HU, 86/55°F limits) have been developed across a wide range of production conditions in Arizona. Optimum ranges in HU accumulations since January 1 are used to describe planting dates to maintain optimum yield potentials with full season varieties. Basic events such as the occurrence of pinhead squares, squares that are susceptible to pink bollworm, and first bloom are described in terms of HU accumulations since planting. Also, the expected ranges of HU's accumulated since planting that are required to accomplish crop cut -out are shown for three general maturity types of Upland cotton.
47
Silvertooth, J. C., E. R. Norton und P. W. Brown. „Cotton Growth and Development Patterns“. College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/210757.
Der volle Inhalt der QuelleAnnotation:
Summaries of cotton crop phenology, as a function of heat units (HU, 86/55°F limits) have been developed across a wide range of production conditions in Arizona. Basic phenological events such as the occurrence of pinhead squares, squares susceptible to pink bollworm, and first bloom are described in terms of HU accumulations since planting (HUAP). Fruit retention guidelines and height: node ratios, which measure a crop's vegetative /reproductive balance, are developed as a function of HUAP. Similarly, the rate of canopy closure is described in terms of HUAP. The use of the number of nodes above the top white bloom to the terminal (NAWB) is developed as a measure of a crops progression towards cut-out. Also, the expected ranges of HU's accumulated since planting that are required to accomplish crop cut-out are shown for Upland and Pima cotton.
48
Jou, Kuen-Da. „Integrated analysis and pattern recognition of Swiss cheese aroma by SPME/GC, SPME/GC/MS and electronic noses /“. The Ohio State University, 1997. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487946776020555.
Der volle Inhalt der Quelle
49
McGinley, Susan. „Grazing Patterns: Elk and Cattle on the V Bar V“. College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/622305.
Der volle Inhalt der Quelle
50
Zerkoune, Mohammed A. „Effect of Messenger® on Cantaloupe Growth Pattern and Yield“. College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2002. http://hdl.handle.net/10150/214943.
Der volle Inhalt der QuelleAnnotation:
An experimental site was selected at Yuma Agricultural Research Center, University of Arizona, to evaluate the effect of Messenger on melon plant growth and yield. Four treatments in completely randomized block design replicated four times were applied to melon planted on 84- inch beds. High Mark open pollinated melon variety was planted on 3-20-2001 using a commercial planter. Treatments included Messenger applied at 3-leaf stage on 5-4-2001 Messenger applied every 14 days starting on 5-15, 5-29, 6-13, 6-27-2001, standard management practices and control. Observations collected included plant mapping and yield. Results were variable, showed no significant effect of Messenger on plant growth and yield. However, there was indication that Messenger may have an effect on plant growth pattern and yield. Messenger applied at 3-leaf stage and repeated applications seemed to induce an early melon formation, increased number of nodes and yield. It was not possible to make recommendation based on one-year results. Further investigation is needed to verify the results obtained from this experiment.