Dissertations / Theses on the topic 'Farming diversity'

The research aimed to investigate and give an understanding of diversity of the farming activities of the beneficiaries of the land reform programme in Chegutu District (Ward 12). The farmers were resettled under both the A1 villagised model and the A2 large scale commercial farming model. The generalised models of A1 and A2 as given by the Government of Zimbabwe do not really characterise the farming and other activities undertaken by beneficiaries of the land reform programme, the study aimed to understand the diversity of the farming activities and hence put the farmers into groups or types as defined by their practices. Diversity in this context means the variation of farming activities of the farmers in the study area. Based on specific parameters, farmers were put in categories/types thereby giving meaning to the diversity of farming activities in the area. The parameters/variables that were used include age of the farmer, the gender of the farmer, the year the farmer was allocated the plot, quality of home infrastructure, the livestock owned, crops produced, the hectarage under each crop and the quantities produced. The other variables that were considered are job status of the plot/farm owner (whether the plot owner have a salaried job or not), the head of the farming activities on the plot/farm and whether the farmer is farming under irrigation or dry land. These parameters, one way or the other, interact with each other thereby influencing the farmer to make decisions that will eventually determine the type of farmer he or she becomes. An attempt was also made to do an economic analysis to assess the profitability of each type of farmers farming operations. By definition, profitability measures the difference between revenue and costs. Revenue is a product of price and quantities of commodities produced while costs are calculated from input quantities and input prices. The hypotheses that were tested are that: There is diversity of farming activities amongst the beneficiaries of the Zimbabwe Land Reform Programme in the study area. The farmers in the study area are farming profitably. The main reason for undertaking the study in the area was that after the Fast Track Land Reform Programme (FTLRP), there was need to understand the dynamics with regard to agricultural production among the farmers. Understanding the diversity of farming activities would then inform policy or intervention strategies to be undertaken in support of the beneficiaries of land reform programme. The other reason why the study area was chosen was because the student is a plot holder in the area and therefore an interested part, in addition to that, general observation points to the likelihood of existence of diversity amongst the farming activities in the area and hence the reason to undertake the study in the area. The administrative, traditional and political authorities were approached to get the authorisation to carry out the study in the area. Random interviews were done as a way of pre-testing the questionnaire and some modifications were done to the initial questionnaire. Several transect walks were also done in the study area to observe and have a general understanding of features and activities in the area. The Extension Officers of sub-divisions/areas within the study area were approached to appraise them of the purpose of the study and also to get their generalised overview of the agricultural set up. Systematic sampling was used per farm targeting a threshold of 10 per cent of the population. Data collection was done from 82 farmers through a patient interview process with the assistance of the Extension Officers who also assisted with transport (motorbikes) to traverse the area. The farmers were generally very co-operative in most instances even though sometimes it was based on them hoping that the research may bring some material support for their farming activities, a notion that was clarified that the research was not going to bring any material support to them at least in the short-term. The last step was the processing of the data which involved both quantitative and qualitative methods in line with objectives and the hypotheses put forward by the study. The typology was developed by an iterative method of continuously refining to ensure a valid and meaningful typology of farmers. An analysis of production activities was also done to check if the farming activities of these beneficiaries of the land reform programme were making any economic sense. The farming activities are basically a function of what resources the farmers have, the conditions under which they farm and the external support received from government or other agencies with interest in agricultural development. The land use practices included a mixture of both irrigated and dry land crop production systems, livestock rearing and vegetable gardening (mainly for home consumption). The farmers are keen to farm on a commercial farming level basis, but non-use of equipment by most farmers in the study area make their production level to remain at subsistence level. Most farmers generally expressed satisfaction with the offer letters as proof of land ownership, but indicated that any strengthening of land ownership especially with title deeds that could allow them to access loans from banks was most welcome.<br>Dissertation (MSc)--University of Pretoria, 2016.<br>Agricultural Economics, Extension and Rural Development<br>MSc<br>Unrestricted

Rural areas of most developing nations are dependent on agriculture. In the most remote areas, sometimes referred to as the â less favored areasâ (LFAs), the economic importance of agriculture is paramount. An important obstacle to development in these areas is that agriculture is at the mercy of nature, which may not be particularly friendly. These areas have remained remote due to natural shortcomings causing economic development to occur slower than more advantaged areas elsewhere. Cochabamba Department, in central Bolivia, is home to some of these LFAs. Most Cochabamban producers are located in the â high climatic riskâ (CIP-WPA) Andean highlands. Farmers in LFAs surrounding Cochabamba city produce (among other things) potatoes for market and home consumption; the potato is the main source of food and income for most residents. Previous studies and anecdotal evidence have shown that Andean potato farmers may plant upwards of 10 varieties of potatoes on small amounts of land (Brush, 92). Because of the low rates of improved crop variety adoption in many LFAâ s, efforts are needed to understand farmer objectives and needs with respect to variety characteristics. The goal of this study is to determine how exposure to risk factors impacts potato planting decisions through demand for potato variety characteristics. The main source of data for this project is a survey of 145 farm households implemented during the last quarter of 2007 in 3 communities of Cochabamba. These data were used to estimate an econometric model that evaluated the role of household, regional and variety characteristics in farmer decision making. Decisions about planting each variety were modeled with a Tobit framework and estimated by the Heckman method (as suggested by Cameron and Trivedi), with the impact of individual variety characteristics restricted to be the same for each variety. Several hypotheses were confirmed such as the importance of yield, though many results were different than expected. Blight tolerance was found to be negatively correlated with selection, although most farmers report taking some kind of action to decrease damage from blight. Possible explanations for this negative correlation are discussed in this paper, and strategies for overcoming these obstacles are suggested.<br>Master of Science

The big importance of insects and their ecological services to the human kind is a big issue in today’s society. Many people question the use of pesticides and are blaming chemicals and conventional farming for the loss of beneficial insects. With this in mind people instead turn to the organic farming. The aim of this study was to try and find out if organic farming benefits the diversity of insects. The study was performed on a farm in South Africa which practice both conventional and organic farming and also has a natural Fynbos field on its property. The insect diversity was compared in these three different fields. The collecting of insects was performed by using two different methods, using pan traps and pitfall traps. This study shows that there is a significant difference in the amount of species among the different fields, with a significant higher insect diversity in the Fynbos compared to the conventional farming area, and the diversity of insects in the organic farming is somewhere between the natural Fynbos and the conventional farming. In conclusion this study stress that we need more understanding about what critical factors in the organic farming that supports higher diversity and the importance of surrounding farms that also may play a role to increase the biological diversity to cultivated fields.

Les fermes maraîchères biologiques françaises sont diverses, allant de systèmes complexes agroécologiques reposant sur la biodiversité et produisant de nombreux légumes différents, à des systèmes simples reposant sur les intrants et produisant peu de légumes différents, ce qui suggère des impacts sur l'environnement différents. L’objectif de la thèse est d’évaluer les performances environnementales de fermes maraîchères biologiques contrastées, au moyen de l’analyse de cycle de vie (ACV). La thèse s’organise autour de : (1) la caractérisation de la diversité des fermes maraîchères biologiques, en mobilisant une typologie réalisée à partir d’enquêtes, et un cadre d’analyse de la diversité des formes d’agriculture ; (2) l’adaptation d’une méthode d’évaluation de la biodiversité au contexte du maraichage ;(3) l’évaluation de trois fermes contrastées par une approche « système » de l’ACV, abordant la ferme comme un tout et où tous les intrants, opérations, et émissions sont rapportés à la production annuelle totale. L’analyse des impacts, exprimés par kg de légume, ha de ferme et Euro de valeur, sur le changement climatique, sur l’eutrophisation marine, sur la biodiversité, la demande cumulative en énergie et l’usage de plastique, fait apparaître de grandes différences entre les systèmes dans leurs principaux postes d’impact, mais ne permet pas d’obtenir un classement clair entre les trois fermes. L’approche « système » de l’ACV correspond au fonctionnement agroécologique et apporte une réponse au défi posé par la complexité de certaines fermes maraichères. L’indicateur d’utilisation de plastique apporte un éclairage nouveau sur une préoccupation croissante<br>French organic vegetable farms are diverse, ranging from complex agroecological systems based on biodiversity and producing many different vegetables, to simple systems based on inputs and producing few different vegetables, suggesting different environmental impacts. The objective of the thesis is to assess the environmental performance of contrasting organic vegetable farms, using life cycle assessment (LCA). The thesis is organised as follows: (1) the characterisation of the diversity of organic vegetable farms, using a typology based on surveys and a framework for analysing farming system diversity; (2) the adaptation of a biodiversity assessment method to vegetable farming; 3) the assessment of three contrasting farms using a LCA "system" approach, considering the farm as a whole and in which all inputs, operations and emissions are related to the total annual production. The analysis of the impacts, expressed per kg of vegetable, ha of farmland and economic value expressed in Euro, on climate change, marine eutrophication, biodiversity, cumulative energy demand and plastic use, revealed large differences between the systems for their main impact contributors, but did not allow a clear ranking of the three farms. The LCA "system" approach corresponds to the agroecological functioning and addresses the challenge posed by the complexity of some vegetable farms. The plastic use indicator shed new light on a growing concern

This study investigates the archaeological contribution of the Shashe-Limpopo Basin, (SLB), a prehistoric landscape with an extraordinary dynamic environment. Research has remained heavily skewed and sites explicitly targeted for investigation were those deemed important for their ability to contribute towards our understanding of the development of social complexity. This study demonstrates that the development of complex social formations represents settlement structures that epitomise interaction of both long and short-term cultural and economic processes and that the organisation of such structures is randomly distributed throughout the landscape. Using remote sensing techniques, archaeological sites on the eastern Botswana side of the SLB have been located, and these attest to the long-term attraction of the basin for human settlement. This is due to the attributes possessed by the landscape and the land-use management strategies employed by the inhabitants in order to cope with the demands of such a structured society in spite of changing climatic conditions. This study argues that the area remained unexplored because of its geomorphological setting and the otherwise poor visibility of archaeological sites that could parallel in size and status neighbouring sites across the political boundaries. Further analysis using GIS spatial and geochemical methods on the sites located suggests a significant influence by the geomorphologic units on the type of activities undertaken which encouraged inhabitants to employ various management strategies to make this apparently hostile environment habitable. Through landscape analysis and archaeological excavations, this study has revealed that the fluctuating environmental conditions made human habitation of the floodplain problematic and restricted settlement and social organisation to its periphery largely on high ground and hill summits, whilst different parts of the floodplain terrain were exploited as water sources, cultivation and grazing resources.

Characterization studies on the genetic diversity among cultivated cowpea (Vigna unguiculata (L.) varieties are valuable tools to optimize the use of available genetic resources by farmers, local communities, researchers and breeders. Eight cowpea (Vigna unguiculata (L.) genotypes ( Vegetable cowpea, Ivory grey, Okhalweni, Fahari, Fahari dark, 97K-1069-8, IT93K-73h, and 129-3) were subjected to molecular, morphological and agronomical characterization. DNA amplification fingerprinting markers were used to evaluate the genetic diversity among the eight genotypes. Nine random arbitrary primers were used to screen the eight genotypes to assess their ability to reveal polymorphisms in cowpea, and seven of them were selected for use in characterizing the total sample. A total of 43 bands were generated which are all polymorphic. On the average, the primers generated a total of 6.1 polymorphic bands. The resulting data-matrix included 43 analysed bands with a total of 344 characters. Neighbour joining analysis was used to generate the dendrogram, clustering the genotypes into two groups at an agglomerate coefficient of 0.30 irrespective of their geographical origins. The results also showed the presence of significant differences in morphological and quality traits among the genotypes. Fahari yielded the highest concentration of crude protein (46.51 mg/mg dry leaf) while Vegetable cowpea yielded the lowest (24.41 mg/mg dry leaf). The influence of manure was also found to be effective by increasing the crude protein content of the genotypes as shown by Fahari dark with an average of 53.53 mg/mg dry leaf as opposed to 39.85 mg/mg dry leaf without manure application. Although some small clusters grouped accessions of the same growth habits, a general lack of agreement between clustering and morphological features was observed. It can therefore be concluded that the significant differences between the molecular genetic analysis using DAF-PCR markers, morphologic characters and yield traits can be important tools to identify and discriminates the different cowpea genotypes.

<p>Den biologiska mångfalden är viktig inom lantbruket. Jordbrukslandskapets mångfald är vacker för människan att se på och spännande och rogivande att vistas i. Mångfalden innehåller även en genbank som kan bli mycket etydelsefull i framtiden. Dessutom innebär oftast en rik mångfald bland ogräsen även en rik mångfald bland insekter och andra djur, däribland skadeinsekternas predatorer, vilket bidrar till produktiva åkrar. Ogräsens mångfald på åkern beror till stor del på geografiskt läge, klimat och berggrund. Även odlingssättet och tillhörande odlingsåtgärder är avgörande för hur åkerns ogräsflora ser ut. En odlingsåtgärd som har ett stort inflytande över ogräsflorans sammansättning, är användningen, eller uteslutandet, av herbicider. </p><p>Uppsatsens fältstudie består av ogräsinventeringar genomförda på två åkrar – en konventionellt odlad och en ekologiskt odlad. Den konventionella åkern är behandlad med syntetiska herbicider och den ekologiska är det inte. Studien visar att den ekologiska åkern hade fler arter, en rikligare mångfald, och många fler plantor än den konventionella åkern. Artsammansättningen tyder på att den konventionella åkern var något mer näringsrik och hade ett lägre pH.</p><br><p>Biological diversity is important in agricultural systems. The diversity of the agricultural landscape is beautiful to the human eye and it provides an exciting as well as soothing environment. Diversity also denotes genetic resources that can be of great importance in the future. Furthermore, a high biological diversity of weeds most often means a high diversity of insects and other animals, among them the predators of pests, which contributes to high productivity of the arable fields. The diversity of weed in a field depends on its geographical location, the climate and the bedrock. Other factors of great importance to the composition of the weed flora are the farming methods (conventional/ecological) and the specific measures used. One measure that has a high influence on the composition of the weed flora is the use, or exclusion, of herbicides. </p><p>The field study of this paper consists of weed inventories of two arable fields – the first cultivated per traditional methods and the second per ecological methods. Herbicides are used in the conventional field but not in the ecological one. The study shows that the ecological field had more secies, a greater diversity, and far more plants than the conventional field. The composition of the weed species indicates that the conventional field had a slightly higher nutritive value and a lower pH value.</p>

The increasing demand for seaweed extracts has led to the introduction of non-native seaweeds for farming purposes in many tropical regions. Such intentional introductions can lead to spread of non-native seaweeds from farming areas, which can become established in and alter the dynamics of the recipient ecosystems. While tropical seaweeds are of great interest for aquaculture, and have received much attention as pests in the coral reef literature, little is known about the problems and potential of natural populations, or the role of natural seaweed beds in the tropical seascape. This thesis aims to investigate the spread of non-native genetic strains of the tropical macroalga Eucheuma denticulatum, which have been intentionally introduced for seaweed farming purposes in East Africa, and to evaluate the state of the genetically distinct but morphologically similar native populations. Additionally it aims to investigate the ecological role of seaweed beds in terms of the habitat utilization by fish and mobile invertebrate epifauna. The thesis also aims to evaluate the potential of native populations of eucheumoid seaweeds in regard to seaweed farming. The initial results showed that non-native E. denticulatum is the dominating form of wild eucheumoid, not only in areas in close proximity to seaweed farms, but also in areas where farming has never occurred, while native eucheumoids are now scarce (Paper I). The low frequency of native E. denticulatum in seaweed beds, coupled with a low occurrence of reproductive structures, indicates that the effective population size may be low, which in turn may be a threat under changing environmental conditions. These results, combined with indications that seaweeds may be declining in East Africa, illustrates the need for attaining a better understanding of the ecological role of tropical seaweed habitats. The studies on the faunal communities of seaweed beds showed that they are species rich habitats, with high abundances of juvenile fish and mobile epifauna (Paper II and III), strongly indicating that these habitats should be considered for future seascape studies and management actions. Productivity in East African seaweed farming is decreasing, and as the current cultivation is based on a single non-indigenous haplotype, a more diverse genetic base has been suggested as a means to achieve a more productive and sustainable seaweed farming. Although our results show that East African E. denticulatum has a lower growth rate than the currently used cultivar (Paper IV), the several native haplotypes that are present in wild populations illustrates that, though a demanding endeavour, there is potential for strain selection within native populations.<br><p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 3: Manuscript. Paper 4: Manuscript.</p>

Made available in DSpace on 2016-06-02T18:57:40Z (GMT). No. of bitstreams: 1 4545.pdf: 14669462 bytes, checksum: 3eacdb08652c8b8f301fc94e1486e34a (MD5) Previous issue date: 2012-06-28<br>This research has been intended to elucidate the family farming diversity of Piedade, in the State of São Paulo and its ongoing repeasantization process within this wide relevant category in the municipality. The case study was made from a theoretical approach on the rural development and involvement as well as over the family farming. Thus, it was noticed that the farming process and the rural environment of Piedade had already experienced countless situations where they could be fit in the agricultural development, rural development and lastly according to the proposal of this research, rural involvement. This is because it has been observed that some farmer families have become more of peasant families with the various strategies they have undertaken and especially because of this, all their practices have been traversed across by the involvement and dynamism of their performers. Moreover, it has been verified that the repeasantization process gathers the most successful and promising strategies in promoting stability, motivation and autonomy to the local farmer families.<br>Esta pesquisa procurou elucidar a diversidade da agricultura familiar de Piedade, SP e o processo de recampesinização em curso dentro desta categoria de ampla relevância no município. O estudo de caso foi feito a partir de um enfoque teórico sobre desenvolvimento e envolvimento rural e também acerca da agricultura familiar. Dessa forma, constatou-se que a agricultura e o meio rural de Piedade já vivenciaram inúmeras situações que podem enquadrá-los nas teorias de desenvolvimento agrícola, de desenvolvimento rural e por fim na de envolvimento rural, proposta por esta pesquisa. Isto porque foi observado que algumas famílias agricultoras estão se tornando mais camponesas com as diversas estratégias que têm empreendido e especialmente por isso suas práticas são atravessadas transversalmente pelo envolvimento e pelo dinamismo que promovem. Além disso, verificou-se que este processo de recampesinização congrega as estratégias mais exitosas e promissoras em promover estabilidade, motivação e autonomia às famílias agricultoras locais.

Household food security has been described with a three-factor definition: 1) the availability of food, 2) the access thereto, and lastly 3) the food utilization patterns and practices. In previous research, both the availability and access to food were studied in a farming community in the Free State Province to understand how these factors contribute to household food security. However food utilization was not investigated at the time. Food consumption patterns of households deserve attention, particularly in relation to food gardens and nutrition, including the cultivation cycle, dietary norms and practices, and methods of food preparation and preservation. By studying utilization patterns of foods, the context of food insecurity and the resultant malnutrition can be better understood. The purpose of this study was to investigate whether the food utilization strategies of a known food crop (spinach) can be used to establish efficient utilization of a new, unfamiliar crop (orange-fleshed sweet potato) in a farm worker community. Three focus group interviews were conducted with a total of 21 participants to determine current food utilization patterns of spinach and orange-fleshed sweet potato (OFSP). The women were asked to describe how they currently utilize these crops in the same focus iv group discussion (although the focus was on the known crop (spinach)) to understand what actions they take during the process of utilization, from access to disposal. They were asked to describe which tools and methods they apply, and who participates in all these various activities. Subsequently, the respondents were asked to perform all these steps while being observed to record current practices. Data from the focus group interviews and the observations were transcribed and categorized under themes. It was found that in addition to a lack of dietary diversity and subsequent malnutrition found discovered in another study of this community, that they are also not optimally utilizing their food. This is as a direct result of lack of access to a variety of food due to monetary constraints, lack of nearby shops, a lack of cultivation and production education about crops that can be home-produced, and a lack of knowledge about nutrition and the importance of a varied diet. A food-based approach to improve the lack of knowledge of home-produced crops and nutrition was, consequently, the focus of this utilization strategy. This information was used to design a food-based strategy to improve the utilization of an unfamiliar crop (OFSP), in areas where the food crop was not being utilized optimally. Although the strategy was developed based on observations and lessons from one specific community, the principal findings were used to develop a strategy that is generic to the implementation of an unfamiliar food crop, and can then be refined for a specific community before implementation. A complete training manual was developed to complement the food-based strategy. The researcher then tested the strategy with agricultural extension officers who are active in communities where food insecurity and malnutrition exist during a training programme hosted by the Agricultural Research Council - Roodeplaat. The agricultural extension officers provided input on the strategy and identified areas for improvement. These recommendations were adapted in a manual to ensure that the developed strategy could be broadly implemented in other communities. The overall conclusion of the study is that it is necessary to investigate and understand all elements of the food utilization system to truly understand the reasons for observed behaviour, habits and practices. Planning and developing a nutrition education programme requires systematic analysis of nutrition and health-related problems in a given community. It is evident that each step of the utilization cycle is equally critical and should enjoy comparable attention to facilitate delivery of nutrient-rich foodstuffs to the end user.<br>Dissertation (MConsumer Science)--University of Pretoria, 2012.<br>gm2014<br>Consumer Science<br>unrestricted

Este trabalho percorre a trajetória de construção do conceito de Segurança Alimentar e Nutricional (SAN), demonstrando as conquistas sociais no campo do conhecimento, explorando seu caráter interdisciplinar e a sua incorporação na academia, através da utilização de um arcabouço teórico-metodológico baseado em uma abordagem multidisciplinar e multiescalar, que a compreende a partir de seis dimensões. Busca-se aprofundar o conceito de agrobiodiversidade, demarcando suas relações com as dimensões da SAN, investigando a existência de um tecido social e sua contribuição para a realização da mesma. Assinala-se, ainda, a aproximação histórica do Programa Nacional de Alimentação Escolar (PNAE) com as questões ambientais, demarcando a abordagem dos Territórios Rurais. O objetivo geral do estudo é analisar como a agrobiodiversidade se articula com as dimensões da segurança alimentar e nutricional no Território Rural Campos de Cima da Serra, RS, a partir do caso do município de São Marcos e do PNAE. A coleta de dados foi realizada em 56 propriedades de agricultores familiares, utilizando-se a entrevista semiestruturada, a turnê guiada e a observação participante. As informações sobre o território foram disponibilizadas pelo CECANE UFRGS e analisados pelo estudo. A análise dos dados utilizou o referencial multidimensional da SAN, por meio dos indicadores propostos para as dimensões ambiental, socioeconômica e política. Para as dimensões nutricional e cultural agregou-se novos indicadores, a partir da análise das preparações culinárias encontradas no município. Os resultados mostram que a agrobiodiversidade compreende 159 espécies alimentares, pertencentes a 49 famílias botânicas, entre plantas exóticas e nativas. Do total de espécies, 15 são listadas pela Portaria Interministerial 163 de 2016 e houve o reconhecimento, pelos agricultores, de 48 etnovariedades, a partir de 12 espécies. Os espaços de cultivos diferenciam-se conforme o destino da produção. Os quintais são mais agrobiodiversos, com espécies destinadas, principalmente ao autoconsumo, demonstrando a relação da agrobiodiversidade com as dimensões ambiental, nutricional e cultural da SAN. Nas lavouras, a diversidade de espécies é mais restrita, com destino comercial, o que contribui para a dimensão econômica. Na dimensão cultural e nutricional, os achados revelam a centralidade da agrobiodiversidade, expressa pelo conhecimento local sobre os processos do ambiente, das espécies, das etnovariedades e por estar presente nas práticas alimentares das famílias, revelando preparações culinárias, com potencial nutricional, inclusive para inserção no PNAE. Soma-se à dimensão nutricional, a importância das 159 espécies que compuseram a alimentação das famílias, configurando maiores disponibilidade de nutrientes. Na dimensão política não foi possível visualizar a centralidade da agrobiodiversidade na expressão da SAN, pela tendência operacional do programa na compra de poucas espécies, com uma atuação enfraquecida dos atores locais. De forma geral, entende-se que a agrobiodiversidade é articuladora das dimensões da SAN, sendo relevante para a sua obtenção no contexto do município. Entretanto, precisa ser fortalecida localmente, especialmente através de sua inserção na dimensão política. Ainda, apesar da existência de um conjunto de atores e instituições articulados na formulação de um tecido social em torno da SAN, este encontra-se enfraquecido, necessitando de ações que contribuam para o seu entrelaçamento em prol da efetiva realização da SAN.<br>This work traverses the path of construction of the concept of food and nutritional security (SAN), demonstrating social achievements in the field of knowledge, exploring your interdisciplinary character and your incorporation in the Academy, through the use of a framework methodological-theoretical based on a multidisciplinary approach and multiescale, who understands from six dimensions. We seek to deepen the concept of agrobiodiversity, demarcating its relations with the dimensions of the SAN, investigating the existence of a social network and your contribution to the achievement of the same. It is noted the historical approach of the Programa Nacional de Alimentação Escolar (PNAE) with environmental issues, marking the approach of of rural territories. The overall objective of the study is to analyze how the agrobiodiversity articulates with the dimensions of the food and nutritional security in the Território Rural Campos de Cima da Serra, Rio Grande do Sul, from the case of São Marcos and the PNAE. Data collection was performed in 56 properties of family farmers, using semi-structured interview, the guided tour and the participant observation. The information about the territory were made available by CECANE UFRGS and analyzed by the study. The data analysis used the multidimensional SAN reference framework, through the proposed indicators for the environmental, socioeconomic and political dimensions. For nutritional and cultural dimensions added-if new indicators, from the analysis of the culinary preparations found in the municipality. The results show that agrobiodiversity comprises 159 species, belonging to 49 botanical families, between exotic and native plants. Of the total of species, 15 are listed by the Interministerial Ordinance 163 of 2016 and there were farmers' recognition of 48 ethnovarieties, from the 12 species. The crop spaces differ according to the production destination. The home gardens are more agrobiodiverses, with species, mainly to consumption, demonstrating the relationship of agrobiodiversity with environmental dimensions, cultural and nutritional of the SAN. In farm fields, the diversity of species is more restricted, with commercial destination, which contributes to the economic dimension. In the cultural and nutritional dimension, the findings reveal the centrality of agrobiodiversity, expressed by the local knowledge about the processes of the environment, species, ethnovarieties and for being present in the feeding practices of families, revealing culinary preparations with nutritional potential, including for insertion in the PNAE. In addition to the nutritional dimension, the importance of the 159 species that composed the feeding of the families configuring greater availability of nutrients. In the political dimension it was not possible to visualize the centrality of agrobiodiversity in the expression of SAN, by the program's operational trend with the purchase of a few species, with a weakened performance of local actors. In general, it is understood that agrobiodiversity is an articulator of the dimensions of the SAN, being relevant for its obtaining in the context of the municipality. However, it needs to be strengthened locally, especially through its insertion into the political dimension. Yet, despite the existence of a set of actors and institutions articulated in the formulation of a social network around the SAN, it is weakened, necessitating actions that contribute to its interweaving in favor of the effective realization of the SAN.

Agrobiodiversity constitutes an essential resource for traditional rural populations. Home gardens are "hotspots" of agrobiodiversity and important loci of in situ conservation efforts. This study seeks to understand the factors affecting gardeners' choices and to assess the accessibility of planting material in rural communities of the Peruvian Amazon. Household surveys and garden inventories conducted in 15 villages of the Corrientes river (n = 300), and case studies in three of these villages (n = 89), allowed to describe the local and regional patterns of garden agrobiodiversity and the structure of planting material exchange networks. Analyses reveal a strong link between species diversity and both household cultural and socioeconomic characteristics, and village ethnicity and size. Planting material flows primarily through matrilineal bonds, from advice-givers to advice-seekers, from old to young and from rich to poor. Farmers with exceptional species diversity, propensity to give and/or expertise are identified and their role in the conservation of cultivated plants is assessed. Expertise is not found to be as closely related to high species diversity as expected, but knowledge and planting stock dissemination go hand-in-hand.

Farm enterprise diversification is an important tool for agricultural producers with respect to risk management. As agricultural producers in Virginia look to prepare their farm businesses for the new millennium, they are increasingly considering non-traditional enterprises and activities for their farms. As producers add new enterprises, they encounter challenges to develop new skills and gather adequate information for their new activities. Virginia Cooperative Extension has the task of providing producers with timely and useful research-based information. As both producers and Virginia Cooperative Extension agents and specialists prepare for the challenges of the changing face of agriculture in Virginia in the next generation, a mutual understanding of the key factors and motivations for enterprise diversification is necessary. This study investigates the key factors, motivations, and information needs of seven diversified farms in Virginia. The implications for producers and Cooperative Extension are outlined, and recommendations are made for Virginia Cooperative Extension, lenders, and agribusiness.<br>Master of Science

L’importance écologique et agronomique des abeilles sauvages dans les paysages agricoles rend cruciale la gestion de ces insectes pollinisateurs. Les abeilles sauvages utilisent plusieurs habitats dans les paysages agricoles, comme les milieux semi-naturels (bois, haies, prairies permanentes), mais aussi les parcelles agricoles. L’objectif de ce travail est de caractériser la structure des communautés de pollinisateurs et le succès de pollinisation le long de gradients de composition et de configuration des milieux semi-naturels ainsi que d’intensité des pratiques agricoles à l’échelle paysagère. Par une approche basée sur les trais écologiques, traduisant des différences d’utilisation des ressources par les abeilles sauvages, nous avons mis en évidence que i) les abeilles sauvages peu mobiles, les espèces solitaires mais aussi les espèces terricoles (nids souterrains) sont plus abondantes dans des parcelles agricoles entourées d’une forte proportion de prairies permanentes faiblement fragmentées, ii) les parcelles entourées d’une forte quantité de lisières forestières présentent une abondance plus importante d’espèces peu mobiles, d’espèces tardives, sociales et polylectiques, iii) les espèces oligolectiques sont filtrées (exclues) dans les paysages fortement boisés car ce sont des espèces profitant de ressources fournies par la mosaïque cultivée. Nous avons aussi mis en évidence que l’effet positif de la proportion en milieux semi-naturels sur la diversité des abeilles sauvages était plus important dans des paysages à la mosaïque agricole gérée de façon intensive. Nous montrons par ailleurs que l’intensité locale des pratiques agricoles peut autant influencer la diversité des abeilles sauvages que la proportion de milieux semi-naturels environnants. Enfin, nous montrons que, suivant les situations, l’abondance des espèces d’abeilles sauvages dominantes ou la présence d’un assemblage d’espèces peu communes peut expliquer le succès de pollinisation. Il semblerait que, dans le cas où le succès de pollinisation répond à l’occurrence d’espèces peu communes, la proportion de milieux semi-naturels aurait une influence positive sur le succès de pollinisation par les abeilles sauvages. Ce travail de thèse démontre l’importance d’espèces peu communes, dépendantes des milieux semi-naturels, pour le succès de pollinisation mais aussi la relation positive entre l’abondance de certains groupes d’espèces et la proportion de milieux semi-naturels. Ce travail permet donc de soutenir l’hypothèse selon laquelle les milieux semi-naturels sont garants du maintien de la diversité des abeilles sauvages et des services rendus par ces dernières. Cependant, l’effet positif des milieux semi-naturels sur la diversité des abeilles sauvages est variable, puisque il dépend des pratiques agricoles à l’échelle locale et paysagère. Les préconisations d’aménagement paysager et de modifications des pratiques ne peuvent donc être faites indépendamment les unes des autres<br>The ecological and agricultural importance of wild bees in farmlands stresses the needs for management strategies for these insect pollinators. Wild bees use multiple habitats in agricultural landscapes, such as semi-natural habitats (woodlands, hedgerows, permanent grasslands) and crop fields. This study aims to characterize the community structure of wild bees and assess pollination delivery along gradients of landscape heterogeneity – based on the composition and configuration of semi-natural habitats – and landscape-wide intensity of farming practices. Using a trait-based approach, based on traits determining resource-use by wild bee species, we showed that i) the least mobile species, solitary bees and ground-nesting species were more abundant in crop fields surrounded by large amounts of little-fragmented permanent grasslands, ii) crop fields surrounded by high amount of woodland edges supported a greater abundance of little-mobile bee species, late-emerging bees, social bees and polylectic bees, iii) oligolectic bee species were filtered out in highly forested landscapes, because these species could thrive on resources provided by the crop mosaic. We also found that the positive effect of the proportion of semi-natural habitats on bee diversity was greater in landscapes with intensively managed crop mosaic. Moreover, we showed that the local intensity of farming practices had as much influence on bee diversity as the proportion of semi-natural habitats. Finally, we showed that, depending on situations, the abundance fluctuations of dominant bee species or the occurrence of an assemblage of uncommon bee species can explain variations in pollination success. In the cases where pollination success responded to the occurrence of uncommon species, the proportion of semi-natural habitats had a positive influence on pollination delivery provided by wild bees. This study shows the importance of some uncommon species, dependent on semi-natural habitats, for pollination delivery but also the positive relationship between the abundance of some species groups and the proportion of semi-natural habitats. This work therefore confirms the hypothesis that semi-natural habitats sustain the diversity of wild bee communities and pollination delivery. However, the positive effect of semi-natural habitats on bee diversity depends on farming practices at the local and landscape scale. Therefore, recommendations on the management of landscape heterogeneity and changes in farming practices cannot be given independently from each other

L'un des moyens pour faire face à la réduction de l'utilisation d'intrants de synthèse est de favoriser durablement les services agro-écologiques de la diversité végétale. Pour cela, l'agriculteur devra adapter ses modes de gestion. Ma thèse s'inscrit dans l'objectif finalisé d'apporter à l'agriculteur, de l'aide à la gestion de cette diversité végétale sur le territoire de son exploitation. Je me suis fixé 2 objectifs de recherche : i) vérifier si les interchamps et le stock semencier constituent des sources d'espèces pour le centre des parcelles agricoles et ii) quantifier l'influence de la dynamique de deux grands groupes de facteurs, représentée sous la forme de trajectoires de parcelles, sur la diversité végétale : les pratiques agricoles et les caractéristiques de la mosaïque paysagère.J'ai mené ce travail sur l'ensemble du parcellaire de l'Installation Expérimentale de l'Inra ASTER Mirecourt, dont les systèmes de production (polyculture-élevage bovin laitier) sont convertis à l'agriculture biologique depuis 2004. J'ai caractérisé la végétation - en place dans les interchamps et au centre des parcelles, et dans le stock semencier - des parcelles en prairies permanentes et en champs cultivés selon deux approches complémentaires : taxonomique au rang de l'espèce et fonctionnelle à partir de sept propriétés rendant compte de la dissémination, de l'établissement et de la survie des espèces végétales. J'ai caractérisé les trajectoires des parcelles, sur une durée de neuf ans, soit à partir des pratiques agricoles mises en œuvre chaque année, soit à partir des caractéristiques annuelles de la mosaïque paysagère. Cette mosaïque correspond aux différentes occupations du sol obtenues à partir de relevés de terrain ou d'enquêtes auprès des exploitants.Je montre que le stock semencier et les interchamps ne constituent pas des sources potentielles d'espèces végétales pour le centre des parcelles, champs cultivés ou prairies permanentes. En revanche, ce sont des refuges importants pour une grande partie des espèces prairiales. Au vu de mes résultats, je fais l'hypothèse que les interchamps sont des puits d'espèces adventices en champs cultivés. J'ai également mis en évidence que le gradient fonctionnel de la végétation prairiale entre la bordure et le centre s'étend jusqu'à 2 m seulement.Enfin, la diversité végétale des parcelles étudiées est principalement influencée par la trajectoire des parcelles selon les caractéristiques de la mosaïque paysagère et par les pratiques agricoles mises en œuvre durant l'année en cours. Les caractéristiques du sol ont un rôle très minoritaire. Ces trois groupes de facteurs expliquent à eux seuls plus des trois quarts de la variabilité de la composition fonctionnelle de la végétation.La gestion de la diversité végétale des parcelles agricoles d'une exploitation peut donc être menée en partie par l'agriculteur. Cependant, compte-tenu des effets de la trajectoire des parcelles selon les caractéristiques paysagères, il est nécessaire de mettre aussi en place une gestion collective de la végétation entre les différents acteurs partageant le territoire<br>One of the means to offset the decrease of pesticide use is to favour agro-ecological services of plant diversity. In this aim, farmer will have to adapt its farming management. My work partly answers to the following applied objective: to bring to the farmer some advices for the management of plant diversity on the farm territory. I have two scientific objectives: i) to verify if field boundaries and soil seed bank are potential sources of plant species for field centres; ii) to quantify the relative influence of dynamics of two factor groups, characterized as field paths, on plant diversity: farming practices and characteristics of landscape mosaïc.I have carried out this study on the experimental farm of INRA ASTER Mirecourt. Its farming systems (mixed crop-dairy systems) have been converted to organic farming since 2004. I have characterized vegetation - established vegetation in field boundaries and in field centres, and vegetation in the soil seed bank - of permanent grasslands and arable fields with complementary approaches: taxonomical approach based on the species, and functional approach based on seven functional properties about dispersal, establishment and persistence of plant species. I have characterized field paths, along nine years, either from farming practices set up on field, either from annual characteristics of landscape mosaïc. I have represented this landscape mosaïc as a mosaïc of distinct land-uses. All of them and their spatialization have been determined from farmer surveys or landscape observations.My results show that soil seed bank and field bboundaries are not potential sources of plant species for field centres, in both permanent grasslands and arable fields. On the other hand, they are efficient refuges for a large part of grassland species. According to my results, I hypothesize that field boudaries are species sinks in arable fields. I also highlight that functional gradient of grassland vegetation in the field edge, between field margins and field centres, is spread until 2 m only.Finally, plant diversity in studied fields is mainly influenced by field path according landscape mosaïc and by farming practices set up the same year of vegetation sampling. Soil characteristics have a minor influence. These three groups of influent factors explain more than 75 % of the functional composition variability of the vegetation in field centres.The management of plant diversity in agricultural fields of a given farm can be partly reach by the farmer. However, according to the effects of field paths about landscape mosaïc, it is necessary to set up a collective management of plant diversity with all actors sharing the studied territory

L'agriculture biologique connaît un essor important en France, comme dans la plupart des pays européens. De profondes mutations traversent ce secteur, et de nouveaux modèles de production et de développement apparaissent. Cette thèse se propose d'analyser ces transformations au niveau de l'exploitation agricole, dans le cadre des sciences de gestion, par le biais de la notion de durabilité (en référence à celle de développement durable). L'étude porte sur un échantillon de 74 exploitations de la région Midi-Pyrénées représentant différentes productions. Une première approche apprécie la durabilité de façon synchronique à l'aide d'indicateurs quantitatifs, pour les dimensions agro-écologique, économique et socio-territoriale. Elle fait état de la diversité des formes de durabilité, en lien principalement avec les logiques de fonctionnement des exploitations. Une deuxième approche aborde la durabilité en tant que processus de changement, d'adaptation et d'innovation, par une étude qualitative des trajectoires d'exploitations et des modes de pilotage. Ces études de cas montrent la diversité des trajectoires d'évolution de la durabilité. En dernier lieu, l'analyse met l'accent sur la dimension émergente et incrémentale des dynamiques collectives d'amélioration de la durabilité.

Face à la pollution généralisée des masses d’eau souterraines par les nitrates et les pesticides, l’agriculture biologique (AB) est présentée comme un outil pertinent pour la reconquête de la qualité des eaux sur les aires d’alimentation de captage (AAC). Ce travail vise à mieux définir l’opportunité d’un développement de l’AB sur des zones à enjeu eau. L’objectif de la thèse est d’évaluer conjointement la faisabilité des conversions sur les exploitations de l’AAC et l’efficacité de ces conversions par rapport aux enjeux de reconquête de la qualité de l’eau.Etudier l’opportunité d’un développement de l’AB à l’échelle territoriale suppose d’instruire la diversité des exploitations et des profils d’agriculteurs sur la zone à enjeu eau. Pour être en mesure de tester l’opportunité des conversions, une méthode typologique permettant d’analyser conjointement la variabilité actuelle des pressions sur les zones à enjeu eau et la propension des agriculteurs conventionnels à la conversion est nécessaire.Pour produire cette typologie, nous avons développé une méthode innovante d’analyse compréhensive des pratiques, centrée sur les principes d’action à l’origine des systèmes de culture. Les principes d’action correspondent à des méta-raisonnements à l’origine de l’organisation concrète des pratiques agricoles sur le territoire d’exploitation. Par l’analyse conjointe du discours des agriculteurs et de la variabilité des règles de décision, nous avons élaboré des typologies basées sur les postures techniques des agriculteurs pour i) identifier des principes d’action associés aux pratiques à risque et ii) dégager des proximités éventuelles entre agriculteurs biologiques et agriculteurs conventionnels. La méthode a été testée sur deux territoires à enjeu eau en Rhône-Alpes, sur lesquels des entretiens semi-directifs ont été réalisés auprès d’exploitants conventionnels et biologiques.Cinq principes d’action génériques à l’origine de l’organisation de l’assolement et cinq principes d’action génériques à l’origine des pratiques culturales ont été dégagés. A partir des différents principes d’action, des typologies des postures techniques ont été produites sur les deux terrains. Les pressions à l’origine de la lixiviation des nitrates et des pesticides ont été évaluées et spatialisées via le recours à des indicateurs agro-environnementaux. Nous avons démontré que la variabilité forte des indicateurs et leur distribution spatiale sur les AAC étaient liées à la diversité des postures techniques entre agriculteurs.Nous avons comparé les principes d’action mobilisés par les agriculteurs conventionnels et les agriculteurs biologiques « références » présents sur les zones à enjeu eau. Par l’étude des spécificités des postures techniques en AB, trois critères de propension à la conversion ont été identifiés. Plusieurs degrés de propension à la conversion ont été dégagés parmi les agriculteurs conventionnels des deux territoires.L’analyse croisée des degrés de propension à la conversion et des différentiels de pressions entre systèmes conventionnels et biologiques nous a permis d’évaluer l’opportunité d’un développement de l’AB sur les deux territoires. Nos résultats ont mis en évidence des niveaux de pression limités quant à la lixiviation des nitrates sur les systèmes biologiques : un développement exhaustif de l’AB à l’échelle des deux AAC entrainerait potentiellement une réduction forte de la lixiviation des nitrates. Néanmoins, l’opportunité d’un tel développement doit être relativisée. Les agriculteurs présentant une propension réelle ou forte à la conversion sont minoritaires sur les AAC. Ensuite, le différentiel des pressions entre systèmes conventionnels et systèmes biologiques diminue à mesure que la propension à la conversion augmente. Pour envisager une diminution forte des pressions sur les zones à enjeu eau, la conversion devrait concerner des exploitants pour lesquels cette conversion est difficilement envisageable à moyen terme<br>Many problems with nitrate and pesticide contamination from agriculture exist in European drinking water catchments. In France, a new mitigation approach aims at preventing water quality degradation in explicitly targeting agricultural non-point source pollutions associated with leaching of nitrates and pesticides. This work aims at assessing the opportunity to develop organic farming in water catchment areas in order to reduce nitrate and pesticide leaching from root zone. The objective was to analyze both i) feasibility of conversions to organic farming on farms concerned by water preservation and ii) the potential impacts of these conversions in terms of nitrate and pesticide leaching reduction.To explore the potential contribution of organic farming in water catchment areas, we develop an innovative typology approach to characterize farmers’ conceptions and strategies related to cropping systems’ organization on the farm territory. Our method was tested in two French water catchment areas characterized by diversified production systems, where semi-structured interviews were carried out with conventional and organic farmers. Resulting typologies of farmers were used to assess leaching risks variability related with current cropping systems and to identify potential similarities between conventional and organic farmers’ conceptions. Nitrate and pesticide leaching risks for cropping systems were assessed and spatialized by using four agro-environmental indicators. Our results show major variations for all indicators at both study sites, for example N-surpluses which range from -105 to 192 kg N ha-1 year-1. These variations are deeply related with diversity of farmers’ conceptions summarized in typologies. To assess proximity of conventional farmers to organic farming, we used typologies to compare conceptions related to organization of cropping systems between conventional and organic farmers. By analyzing specificities of organic farmers’ conceptions, we determined three main criteria of proximity to organic farming; these criteria were then used to identify various degrees of proximity to organic farming among conventional farmers in the catchment areas.To assess potential contribution of organic farming to water preservation in catchment areas, we firstly compared nitrate leaching risks between conventional and organic cropping systems. Our results reveal low leaching risks from organic systems, characterized by reduced N-surpluses and lower bare soils frequencies in autumn. According to these results, massive development of organic farming should decrease nitrate leaching in our two water catchment areas. However, analysis of similarities between conventional and organic farmers’ conceptions shows that a majority of farmers are characterized by a low level of proximity to organic farming. Moreover, the farmers who show strongest similarities with organic farmers’ conceptions are already those with low leaching risks cropping systems. To significantly lower nitrate leaching risks, conversions should concern conventional farmers with low degree of proximity to organic farming

A pesquisa que deu origem a esta dissertação trabalhou com a temática sobre assentamentos rurais. Para isso, foi fundamental apresentar uma revisão teórica sobre a reforma agrária no Brasil e, neste contexto, o surgimento dos projetos de assentamentos rurais no país. Do mesmo modo, apresentou-se o debate sobre as formas de cooperação do trabalho, destacando as diferenças entre os projetos cooperativistas tradicionais e a concepção cooperativa dentro do Movimento dos Trabalhadores Rurais Sem-Terra – MST. Após a definição do objeto de pesquisa, que correspondeu às características presentes na relação entre a escolha pela filiação em determinado grupo e as dinâmicas dos processos de organização econômica e social correspondentes, passou-se à elaboração da seguinte pergunta: o que é decisivo para as famílias assentadas no momento de optar por um ou outro projeto, um ou outro arranjo organizativo, e quais são as características das estratégias de organização social e produtiva daí derivadas? Para este fim traçaram-se, principalmente, os seguintes objetivos: (i) entender os aspectos que levaram à gradativa saída de algumas famílias do conjunto da cooperativa e a opção por organizarem-se social e economicamente em lotes individuais, e (ii) relacionado ao anterior, verificar as estratégias e práticas de diversificação social e produtiva de cada grupo e em que medida elas possibilitaram a emergência de processos endógenos de desenvolvimento rural. Privilegiou-se uma metodologia qualitativa de análise, sob a qual fez-se uso da técnica de observação participante e da aplicação de entrevistas junto aos dois grupos. Pôde-se concluir que os motivos que levaram a saída das famílias da cooperativa, expressos no descontentamento com o equivalente econômico pago pelo seu trabalho e com as decisões coletivas, explica-se por elementos presentes na composição do que a literatura clássica denominou de campesinato tradicional. No entanto, a análise da organização social e as estratégias produtivas traçadas por ambos os grupos permitiram identificar a constituição de uma base permanente e de recursos temporários utilizados no processo de produção. Foi possível observar que o uso da força de trabalho, a organização dos espaços produtivos, a quantidade e a qualidade das áreas ocupadas com os cultivos, e as próprias relações internas e externas ao assentamento, potencializaram a existência de algumas práticas endógenas de produção agropecuária. Além disso, verificou-se que a relação dos assentados com os agentes de desenvolvimento rural ocorre, fundamentalmente, através dos serviços prestados pela EMATER e outros agentes públicos que possuem relativa importância pelo trabalho de mediação que realizam, pelo planejamento e pela aplicação de políticas públicas como o PAA.<br>This dissertation research was carried out with the aim at to discuss rural settlements. Therefore, it was essential to present a theoretical review about this reform in Brazil and, in this context, the emergence of the projects of rural settlements in the country. Similarly, it was presented the debate about ways of work cooperation emphasizing the differences between the traditional cooperative projects and the cooperative conception in the Landless Squatters Movement – MST. After defining the research object, that corresponds to the characteristics that are present in the relationship between the choice for membership of particular group and the dynamics of the processes of economic and social organization concerned, the following question was set: what is decisive for settled families at the time of choosing either project, either organizational arrangement, and what are the characteristics of the strategies of social and productive organization from it derived? In view of that , the following objectives were set: (i) understand the reasons that lead up some families to gradually desist from the cooperative group and the option to organise themselves socially and economically into individual lots and (ii) related to the previous item, check the strategies and practices of social and productive diversification of each group and in which extent they enabled the emergence of endogenous processes of rural development. It was chosen a qualitative methodology of analysis in which a technique of participant observation and the application of interviews with the two groups was used. It was concluded that the reasons for the families desistence from the cooperative, expressed on the dissatisfaction with the economic equivalent paid for his work and the collective decisions, is explained by elements present in the composition of the classical literature called traditional peasantry. However, the analysis of social organization and production strategies outlined by both groups has identified the establishment of a permanent base and temporary resource used in the production process. It was possible to observe that the use of the workforce, the organization of productive space, the quantity and quality of the occupied areas with crops, and their own internal and external relationships to the settlement, contributed for the existence of some endogenous practices of production industry. Moreover, it was found that the relationship of the settlers with the agent sof rural development occurs basically through provided services by EMATER (a state public company in Brazil to implement the state government's agricultural policy and provides technical assistance to farmers) and other public agents that have relative importance on the mediation work, which perform the planning and implementation of public policies such as PAA.

碩士<br>國立中興大學<br>土壤環境科學系<br>90<br>Soil microbial communities are the most diverse in the earth. However, they are not well known at this moment. They are close related to nutrient cycling, plant growth and the other organisms. Therefore, they are important to soil quality. The sustainability of soils is much dependent on the biodiversity in soils. The purples of this study were to investigate the effects of different organic fertilizers, application rates, and different rotation systems on soil microbial diversity, tested by Biolog microplates method. The experiment field was located at Hosing ecological farm, Gaoxyong district agricultural experiment station. The soil microbial communities under chemical fertilization utilized less carbon souses, especially under flooded condition, whatever the rotation was one rice crop or three rice crops in two years. Proper application of organic fertilizer increased the carbon utilization by soil microbial community. However, overdose of organic fertilizer decreased the utilization of carbon sources. A formulated organic fertilizer, named as functional compost, increased the utilization of carbon sources mostly. The metabolic potentials of soil microbial communities under organic fertilizers were higher than that under chemical fertilizer. Overdose of organic fertilizer (14400 kg ha-1 of soybean refuse compost) decreased the metabolic potentials. The metabolic potential of the soil microbial communities under cow manure compost application was lower than that under the other kind of composts. The similarity analysis showed that application of 14400 kg ha-1 of soybean refuse compost changed the structures of soil microbial communities dramatically. The principal component analysis showed that the primary factor affecting the soil communities was the application of organic fertilizers, and the second factor was flooding of the soils. The first component in the experiment dealing with the rates of organic fertilizers was the amount of application and the second component was soil moisture. In the experiment dealing with the kinds of organic fertilizers, the soil moisture was the primary factor affecting soil microbial communities.

Surrogates of biodiversity are necessary tools for guiding the effective conservation of biodiversity. One of the best known approaches to assessing biodiversity is cross-taxonomic surrogacy, which is underpinned by the hypothesis that selected taxa (i.e. the surrogate) can provide useful and commensurate information on other components of biodiversity (i.e. the target). In this thesis, I examined the effectiveness of cross-taxonomic surrogacy by assessing cross-taxonomic patterns of congruence among ecologically important vertebrate and invertebrate taxa, and with respect to time and different landscape contexts. Using a long-term dataset, I first assessed patterns of cross-taxonomic congruence between three vertebrate groups over a 15-year period. My analyses revealed that patterns of cross-taxonomic congruency were inconsistent over time, varied among the taxa compared, and across different landscape contexts. Bird and mammal diversity were weakly concordant, but strengthened with time. However, there was little association between either birds or mammals, and reptiles. My findings suggested that cross-taxonomic surrogacy has limited effectiveness in heavily disturbed landscapes such as Nanangroe where ecological communities are expected to exhibit high temporal variation. Second, I examined the responses of two ecologically important insect groups (wild bees, beetles) to landscape context. Here, I found that species richness of bee assemblages showed no clear responses to different landscape contexts, unlike beetle assemblages. These patterns persisted even when both insect assemblage was partitioned into functionally-defined groups. Further analyses showed that both groups were responding to different landscape and vegetation components. My findings here demonstrated that wild bee diversity is weakly congruent with beetle diversity, and that surrogacy relationships between even charismatic insects should not be assumed without rigorous testing. Third, I examined how sets of woodland patches prioritised to best conserve each surrogate group (bird, herpetofauna, bee, beetle, tree) represented the other four groups using a complementarity-based approach. Thereafter, I compared these findings with correlation-based analysis to determine patterns of cross-taxonomic congruence. I found that patch sets selected to optimise representation of the surrogate varied in how it incidentally represented other taxa. Beetles achieved the highest incidental representation of other taxa while bees and trees performed the worst. Yet, beetles were the most costly taxa to conserve given the large number of patches needed to meet beetle targets, an ecological consequence of the high diversity and compositional turnover of beetle assemblages. My findings show that species diversity of any taxa should be a pertinent consideration in identifying cross-taxonomic surrogates to prioritise sites for biodiversity conservation. Fourth, I performed a meta-analytical review of the global surrogate literature to assess the effects of anthropogenic disturbance on cross-taxonomic surrogacy in terrestrial systems. Drawing from a dataset compiled from 146 studies, my analyses revealed that anthropogenic disturbance plays an important role in shaping patterns of cross-taxonomic congruence, especially at landscape and regional scales. Spatial scale was an important predictor of cross-taxonomic patterns, but only at very large scales. In conclusion, my findings caution against extrapolating cross-taxonomic surrogates across landscapes subjected to different levels of disturbance and spatial scales to assess biodiversity. Focusing on ubiquitous, human-modified landscapes, my work underscores a number of practical and theoretical issues concerning the use of cross-taxonomic surrogacy. By collectively or individually examining the roles of time, landscape context and habitat structure with respect to diverse groups of vertebrate and invertebrate taxa, my thesis makes explicit the need to consider important ecological processes that can better guide the use of biodiversity surrogates in conservation.

碩士<br>國立中興大學<br>土壤環境科學系所<br>103<br>Chemical fertilizers and chemical pesticides are commonly used to increase soil fertility and reduce plant pathogen in conventional farming. To achieve agricultural production in a more sustainable way, integrated managements instead of overdose use of agricultural chemicals are adopted to obtain high quality and yield of crops meanwhile maintain soil quality. The distribution of microbes which participate in nutrient transformation may be changed spatially or temporally in a dynamic soil ecosystems. In the present studies soil microbial diversity as influenced by long-term organic and conventional farming were evaluated in banana plantation soils. Soil samples were collected from the established fields in Taiwan Banana Research Institute during 2011-2014. Basic properties of soil such as water content, pH, EC and organic matter content were determined. Approaches to study metabolic and population diversity in banana plantation soils were conducted. These included the culture-dependent and culture-independent methods to obtain viable number of different bacterial groups, community level of physiological profiles and microbial community structure under different long-term farming systems. The results demonstrated that water content, pH and organic matter content were the highest in 17-year organic farming soils and lowest in long-term conventional farming soils. Metabolic potentials of fast-growing microbes in 7-year organic farming soils were generally higher than that in 17-year organic farming soils or conventional farming soils, as revealed by richness, average well color development and diversity index. The SAWCD value demonstrated that carbohydrates were well utilized by fast-growing microbes in soils under organic farming than that under conventional farming. α-Malic acid, β-Methyl-D-Glucoside, D-Cellobiose, L-Serine and N-Acetyl-D-Glucosamine were positively correlated with organic farming, while L-Asparagine and Pyruvic Acid Methyl Ester were positively correlated with conventional farming, which were verified by principle component analysis. Soils under organic farming harbored slight higher number of heterotrophs, free-living nitrogen fixers and tricalcium phosphate solubilizers than that in conventional farming soils. Members belonging to the phylum Firmicutes were dominated in all the three farming soils, and diverse Bacillus lineages at species or strain level were resolved by cultivated-based method. Microbial community structure of soils under three farming systems was compared through 16S rDNA clone library construction and sequence analysis. The 17-year organic farming soils have the highest percentage of unclassified bacteria (at the phylum level) while members belonging to Proteobacteria were dominated in 7-year organic farming soils and conventional farming soils. A higher percentage of clones was occupied by the phylum Acidobacteria in conventional farming soils, which may be related to soil deterioration.

Tese de Doutoramento em Biociências, na especialidade de Ecologia, apresentado ao Departamento de Ciências da Vida da Faculdade de Ciências e Tecnologia da Universidade de Coimbra<br>The olive crop (Olea europaea) is a significant land use type with high importance in the Mediterranean countries. The olive tree is susceptible to the attack of pests that can cause significant losses. Among the community of arthropods of the olive grove, spiders are predators occupying the highest trophic level, hunting mainly insects in all their instars. Thus, they can be useful natural control agents of olive pests; however, the intensification of farming practices can affect their abundance and effectiveness. Aspects such as the conservation of a heterogeneous agricultural landscape and the maintenance of ecological infrastructures can be seen as part of a strategy to achieve sustainability and promote conservation biological control. The main objectives of this thesis were to study the diversity patterns of Araneae through an increasing gradient of olive grove farming practices, study the effect of ecological infrastructures as sources of non-prey foods on the survival and behavior of Araneae, study the mechanisms of foraging of Araneae, and develop tools that aim at promoting the diversity of Araneae in the olive grove agroecosystem. The structure of the Araneae assemblages under different farming practices was studied by sampling selected olive groves in northeastern Portugal at the soil, trunk, and canopy levels, as well as the adjacent semi-natural areas (Mediterranean shrublands). The experimental design, the number of stones in the soil, the percentage of vegetation, moisture, and crop management were used to model the diversity patterns found across the olive grove and its surrounding landscape. The effect of ecological infrastructures and mechanisms of foraging of Araneae were investigated through laboratory assays using selected species of spiders as models for different functional groups. The effect of non-prey foods (glucose at 0.5 M; aphid honeydew; black scale honeydew; a mixture of glucose 0.5 M, phenylalanine 0.1 mM, proline 0.1 mM, and tryptophan 0.1 mM; honey at 10%, and pollen at 10%) on the longevity and food selection, and the functional response and prey preference were studied on immatures and adults of spiders respectively. Moreover, two simulation-based tools were developed: an R package (simaR) that simulates the functional response of a predator and calculates its maximum attack rate, and an educational individual-based model (EcoPred) that simulates a top-down trophic cascade controlled by the pressure exerted by two model predators on a model pest within a hypothetical agricultural landscape. Nine functional groups (ambushers, foliage runner hunters, ground hunters, orb-web builders, sheet web builders, sensing web-builders, space web builders, stalkers, and wandering sheet/tangle weavers) were found to encompass a community that changed significantly across the horizontal and vertical gradient across the olive crops. Philodromus lividus was the most abundant species in the canopy, Erigoninae was the most recorded group on the trunk, and the ground was dominated by Thanatus vulgaris whereas the adjacent shrublands were dominated by Nomisia exornata. The number of stones was found to significantly enhance the overall diversity of spiders, the abundance of immature individuals and abundance of ground hunters. The overall survival of immatures of Haplodrassus rufipes (ground hunters) and Synema globosum (ambushers) fed on non-prey foods significantly increased compared to individuals fed on water. When different non-prey food items were offered together, the exploring rate was significantly higher for H. rufipes than for S. globosum. H. rufipes chose to feed on honey whereas S. globosum chose the mixture treatment. The most chosen food items corresponded with those that provided the highest longevities in both species. The most and the least efficient adult spiders against the Mediterranean fruit fly Ceratitis capitata in laboratory were H. rufipes and S. globosum respectively. However, opposite results were obtained when alternative preys (crickets and moths) were supplied. Araniella cucurbitina (orb-weavers) significantly changed its functional response with the presence of alternative preys as well. Considering the prey preference, the heavy, long-sized and highly motile preys (Acheta domesticus) were avoided whereas light, small-sized and moderately motile preys (C. capitata) were preferred by the three guilds of spiders. The effect of temperature on the attack rate of two guilds of spiders against C. capitata was assessed using the simaR package. It was found that the maximum attack rate of A. cucurbitina (orb-weavers) on C. capitata significantly decreased as the temperature increased whereas the opposite pattern was found for S. globosum (ambushers). On the other hand, EcoPred reflected the changes on a fly population within a simulated olive crop according to the mortality rate caused by the predation of two guilds of spiders and energy loss, the energy gain by feeding on flowers, and the reproduction rate in olives. The model was used to teach different aspects of biological control to 26 students achieving very good results in terms of acceptance and interest in the learning method. In conclusion, each guild of spiders may include efficient predators against pests according to its hunting strategies and the ecological exploited niches. Different aspects related to agricultural management such as the presence of adjacent shrublands, the conservation of soil microhabitats (e.g. hedgerows, stonewalls, and stones on the ground), and maintaining weed strips may allow the spillover, increase the number of shelters, and provide valuable supplementary food resources for spiders thus playing an important role on their contribution to biological control of pests in the olive grove agroecosystem.<br>A oliveira (Olea europaea) é uma espécie de grande importância na bacia do Mediterrâneo. No entanto, esta cultura é afetada pelo ataque de várias pragas que podem causar perdas significativas. Entre a comunidade de artrópodes do olival, as aranhas são predadores que ocupam o nível trófico mais elevado, consumindo principalmente insetos em todos os seus instares. Por esta razão, as aranhas podem ser importantes inimigos naturais de pragas da oliveira, embora a sua abundância e eficácia possa ser influenciada por vários fatores bióticos e abióticos. Assim, a manutenção de uma paisagem agrícola heterogénea pode ser parte de uma estratégia para alcançar a sustentabilidade e promover a proteção biológica por conservação. Os principais objetivos desta tese foram estudar os padrões de diversidade do táxon Araneae ao longo de um gradiente de práticas agrícolas no olival, estudar o efeito de infraestruturas ecológicas, como fontes de recursos, na sobrevivência e no comportamento do táxon Araneae, estudar os seus mecanismos de predação, e desenvolver meios que visam promover a sua diversidade no olival. A influência de diferentes práticas agrícolas na estrutura da comunidade do táxon Araneae foi estudada em áreas de olival no nordeste de Portugal (ao nível do solo, tronco e copa) e em áreas semi-naturais adjacentes (mato mediterrânico). O tipo de desenho experimental, o número de pedras no solo, a percentagem de vegetação, a humidade e a gestão agrícola foram utilizados na modelação dos padrões de diversidade encontrados no olival e na sua paisagem circundante.O efeito das infraestruturas ecológicas e dos mecanismos de predação do táxon Araneae foram estudados, com recurso a ensaios laboratoriais, utilizando espécies de diferentes grupos funcionais. O efeito de diferentes itens alimentares não-presa (glicose 0,5 M, melada de afídeo, melada de cochonilha-negra; uma mistura de glicose 0,5 M, fenilalanina 0,1 mM, prolina 0,1 mM e triptofano 0,1 mM; mel a 10% e pólen a 10%) na sobrevivência e escolhas alimentares, assim como a resposta funcional e preferência por distintos tipos de presa foram estudadas em aranhas juvenis e adultas respetivamente. Além disso, foram desenvolvidas duas ferramentas de simulação: um pacote de funções em R (simaR), que simula a resposta funcional de um predador, e um modelo baseado em indivíduos (EcoPred), que simula uma cascata trófica de uma praga modelo controlada pela população de dois tipos de predadores. Nos olivais em estudo, foram identificados nove grupos funcionais do táxon Araneae: emboscadores, caçadores nas folhas, caçadores no solo, construtores de teia orbicular, construtores de teias laminares, construtores de teias de deteção, construtores de teias espaciais, acossadores e construtores itinerantes de teias laminares/emaranhadas. As comunidades diferiram significativamente quanto à composição ao longo dos gradientes horizontal e vertical. Philodromus lividus e Thanatus vulgaris foram as espécies mais abundantes na copa e no solo respetivamente, e a subfamília Erigoninae foi o grupo dominante no tronco. As áreas de mato adjacente foram dominadas por Nomisia exornata. A diversidade global de aranhas e a abundância de indivíduos juvenis e de espécimes caçadores no solo foi significativamente maior em áreas com um maior número de pedras. A sobrevivência global de juvenis de Haplodrassus rufipes (caçadores no solo) e de Synema globosum (emboscadores), alimentados com itens não-presa, aumentou significativamente em comparação com indivíduos alimentados com água. Em ensaios alimentares de múltipla-escolha, Haplodrassus rufipes selecionou maioritariamente o mel e apresentou uma taxa de exploração significativamente maior do que S. globosum, que selecionou o tratamento de mistura. Os itens alimentares mais escolhidos corresponderam àqueles que proporcionavam maiores longevidades em ambas as espécies. Os adultos de H. rufipes e S. globosum mostraram ser, respetivamente, os mais e menos eficientes quanto à mortalidade infligida em mosca-do-Mediterrâneo, Ceratitis capitata. A taxa de ataque de S. globosum e de Araniella cucurbitina (construtores de teia orbicular) aumentou significativamente em ensaios de resposta funcional de múltipla-escolha quando comparada com ensaios com uma única espécie de presa. Considerando a preferência por tipologias de presas, verificou-se que as presas mais pesadas, de tamanho maior e altamente móveis (p.e., Acheta domesticus), eram evitadas pelos três grupos funcionais de aranhas, enquanto que as presas mais leves, de menor tamanho e moderadamente móveis (p.e., C. capitata) eram preferidas. O efeito da temperatura na taxa de ataque de dois grupos funcionais de aranhas contra C. capitata foi avaliado usando o simaR. Verificou-se que a taxa máxima de ataque de A. cucurbitina em C. capitata diminuiu significativamente com o aumentou da temperatura, contrariamente ao ocorrido para S. globosum. O modelo EcoPred foi utilizado para ensinar, a 26 estudantes do ensino secundário, os diferentes aspetos relacionados com a proteção biológica. Depois de testarem o modelo, os estudantes mostraram muito interesse neste método de aprendizagem. Em conclusão, cada grupo funcional de aranhas inclui espécies predadoras de pragas sendo que a sua ação varia de acordo com as estratégias de caça e os nichos ecológicos explorados. Os vários aspetos relacionados com a gestão agrícola, tais como a presença de matos adjacentes, a conservação de micro-habitats no solo e a manutenção de faixas de plantas espontâneas, poderiam promover o aumento do número de refúgios e proporcionar recursos alimentares suplementares às aranhas, desempenhando um papel importante na proteção biológica por conservação contra as pragas da oliveira.

The topic of this thesis deals with effects of different farming management on diversity and abundance of butterfly fauna in České středohoří and neighbouring areas. It shows that ecological management is more friendly to endangered species of butterflies.

<p>Arbuscular mycorrhizal fungi (AMF) are best known for their potential to help plants acquire nutrients, especially phosphorous. These microbes improve soil health by promoting soil aggregation and carbon sequestration, and further benefit plants by helping them withstand biotic and abiotic stress. Currently, there are 200 recognized species of AMF within the phylum Glomeromycota. Recent studies indicate that individual AMF species differ in the benefits they provide, with some even acting as parasites. Moreover, AMF community composition can be altered by soil and crop management practices, but the effect of these changes on the benefits conferred by AMF are still not well understood. Consequently, the goal of this study was to determine how two widely used crop management systems can alter the composition of AMF species, and affect the potential for these communities to promote the productivity and drought tolerance. To accomplish this goal, we collected AMF inoculum from a long-term crop systems trial comparing organic and conventional management for use in greenhouse trials where we subjected plants to drought. We collected AMF inoculum during mid-summer when differences between the two management systems were likely cause larger effects on AMF communities, and again in autumn after harvest to see if differences in AMF communities would persist. We determined AMF species composition using next generation sequencing. Results of this study confirm that soil-building practices commonly used in organic farming systems can improve soil health and increase the productivity of food-grade soybeans. They also demonstrate that AMF communities in Indiana croplands are highly diverse, and some of these taxa can improve soybean growth and help plants tolerate water stress. Although the overall diversity of AMF communities did not differ between the organic and conventional management systems in mid-summer, individual AMF taxa did differ between the systems, which were likely responsible for the greater tolerance to water stress observed when plants were amended with inoculum from the organic system. AMF communities present during autumn were significantly different between the two crop management systems, but did not result in differences in drought tolerance of soybeans, indicating that the loss of key AMF taxa in the organic system from the first relative to the second experiment was likely responsible. Finally, plants grown using inoculum from both crop management systems in autumn had greater tolerance to water stress than plants that received a AMF commercial inoculum. This provides further evidence that individual AMF species vary in the benefits they provide, and that the presence of a diverse consortium of AMF species is needed to optimize plant health and productivity in agricultural systems. Agricultural producers should consider incorporating soil-building practices that are commonly used in organic farming systems such as planting winter cover crops, to improve the health of their soil and enhance the productivity of their crops. <b></b></p> <br>

Despite research focused on the control of E. saccharina Walker (Lepidoptera: Pyralidae), it remains the most destructive pest of sugarcane in South Africa and therefore a shift in the approach to the control of this insect was required. Habitat management techniques were employed through trials to understand the mechanisms used by insect pests in their host plant oviposition behaviour. Indigenous and beneficial non-crop plants, which could be used to attract insect pests away from sugarcane were identified and tested. An African grass, Melinis minutiflora, shown to be repellent to lepidopteran stemboring pests, was used in field trials in sugarcane. Eldana saccharina was shown to be fairly indiscrimate in choosing host plant species. Oviposition trials showed that females made no choice for host plants oviposition based on the volatiles released by those plants. Females showed no preference for males over test plants. But did consistently move and make a plant choice more often than male moths. Moths were not attracted by the volatile stimuli of a host plant and the availability of cryptic sites might be a factor that influenced ovipositing females to choose a host plant. Field trials tested the repellent action of Melinis minutiflora against E. saccharina and were shown to be more effective over a big field with space for M. minutiflora to establish thick undergrowth alongside a field plot. The other field sites showed no significant effect from M. minutiflora intercropped into treatment plots, or a slight negative effect. Later sugarcane planting times in relation to the grass planting time was a possible reason for the positive result in only two field sites allowing the grass to grow and establish before the sugarcane competed with the grass for sunlight. A cost benefit analysis of planting a hectare of sugarcane with M. minutiflora showed an economic benefit linked to reduction in E. saccharina infestation. Field sites with low population pressure from E. saccharina would not yield the economic benefit of planting this grass. There was no significant loss in the height, density or sucrose yield (ERC% cane) between control and treatment plots in the field plots due to the presence of M. minutiflora. Comparison of weed biomass between treatment and control plots showed a significant reduction in the treatment plot where M. minutiflora out-competed the weeds already present. This grass was advantageous in the sugarcane field as it sometimes reduced moth infestation but did not significantly compete with sugarcane and showed weed suppressing potential.