有機農業不僅可產出自然安全的農產品，同時亦得創造優質的農業環境，提供環境公共財與社會公共財，然而這樣的公共財，難以由單一農民提供，而是必須透過同一地區的農民以及利益相關者的共同參與，展開集體行動，才得以有效供給。 宜蘭縣三星鄉行健村是個特殊的案例，有部分農民為推行有機農業，乃成立全台灣第一個由農友組成的有機生產合作社，展開揚棄慣行農法的集體行動，藉由社員互信互助，實踐不施農藥、化肥的栽培，成效初具。然而，行健有機村的知名度雖逐漸提升，但實際上，有機村的名號與實際發展似乎不相襯，目前村內有機耕作面積只佔全村耕作面積的五分之一。因此，本研究以集體行動之理論分析框架，檢視行健村以集體行動促進有機農業發展之可能性。並以文獻分析法、深度訪談法、斷面步行法探究行健村有機農業發展之困境，分析檢討目前的集體行動社會網絡互動模式有何不足之處，期能提供改善建議，以促進該村有機農業發展的可能性。 研究結果顯示該村有機農業發展確實需要集體行動，始能獲致生產及非生產性的共同利益，然而村內網絡間的社會資本不足，以致欠缺發展有機村的共同目標，推展有機農業的集體行動難以擴大，再加上網絡間整合不佳，導致外部資源的投入未有相對應的成效，復又，行健合作社的制度安排不佳，導致營運困境，影響有機村的推展。而中央與地方政府合作不佳，以及現行政府的有機政策導向都關鍵地影響慣性農民轉型有機農業之意願。 本研究認為應增加村內社會網絡間彼此溝通交流之頻度，且行健合作社應重新檢討內部的制度安排，以利促進眾人一心發展有機村之集體行動；而政府方面，應設法改善有機農民之通路、建立有機專區的誘因機制，並且思考補貼政策的轉型，輔以加強消費者食農教育，使有機農業的供需市場擴大並產生互利的良性循環，如此方能讓更多農民願意投入有機耕作，或能真正發展成為兼具生產、生活、生態的「有機村」。 / Organic agriculture not only produces healthy and natural food, but also co-produces environmental public goods and social public goods. However, this kind of goods need to be provided efficiently only by farmers cooperatively, rather than individual. This case study is located in Xingjian village, Sansing Township, Yilan County, where some farmers set up “Xingjian Organic Production Cooperative” to stimulate organic farming development in the village. In this Cooperative, they trust and help each other, trying to persuade other farmers out of using chemical fertilizers and pesticide in farming, and further more, expanding the collective action. To date, some people have been participating in this collective action, as a result, have tackled local agri-environmental issues and provided agri-environmental public goods to some degree. However, as the growing reputation of “Xingjian Organic Village”, the organic farming area only accounts for 20 percent of the total arable land. Therefore, this research using collective action theoretical framework to view the possibility of the Xingjian in promoting organic farming development. This research adopts three ways- literature, in-depth interviews, transect walks, to explore the obstacle of Xingjian village in promoting organic farming development, and to analysis the problem of social network interaction. The result shows that organic agriculture development in the village do need collective action to attain production and non-production of common interests. However, the collective action of organic farming is difficult to expand due to lack of social capital in the village between the networks, and the lack of the common goal in this village. Thus, the input of external resources do not correspond to its performance. Further, institutional arrangements in Xingjian cooperatives functions poor, leading to its operational difficulties. Besides, poor Cooperation between central and local government, as well as the current policy orientation of government, both play a crucial role in affecting farmers' willingness to change conventional farming to organic farming. This study suggests that social networks between the village should connect closely by communicate with each other frequently, and Xingjian cooperatives should review its institutional arrangements, in order to facilitate the collective action of “Xingjian Organic Village”; and the government should try to improve organic produce’s access to market, establish incentives about organic agriculture zone, transfer subsidies policy to organic agriculture, and strengthen consumer’s organic education, so can make more farmers willing to invest in organic farming, or can really develop a production, life and ecology combined "organic village".

The study aimed to investigate the hygiene quality of fresh agricultural produce, irrigation water and compost from four cooperatives (Jabulani, Nungwane, Senzakahle and Siyazenzela) supplying the uMbumbulu Agri-Hub Non-Governmental Organisation. In addition, the influence that socio-economic characteristics such as age, gender, level of education and training had on the uMbumbulu farmers’ hygienic practices was investigated. Questionnaires, key informant interviews and laboratory analysis were used to collect data. The most probable number (MPN) method, a microbiological technique, was used to quantify selected hygiene indicators (i.e. total and faecal coliforms including Escherichia coli) from compost, irrigation water and leafy vegetables (spinach and lettuce) during the months of October, November and December 2011. Microbiological analysis on lettuce and spinach produced by the four Agri-Hub cooperatives confirmed that these vegetables were safe to eat and unlikely to cause sickness. The irrigation water sources, vegetables and compost faecal coliform levels met national standards with faecal coliforms of <1 000 MPN/100ml for irrigation and<200 MPN/g for the leafy salad vegetables. Compost faecal coliform levels were <1000/g and E. coli levels of <30 MPN/g, these levels decreased over the 3 months. Descriptive statistics such as the Chi-Square test using IBM SPSS and a logistic regression was performed using the STATA 11 software. The sample consisted of 60% female and 40% males, most of which (73%) were above the age of 40. A total of 60% of respondents received income from farming activities, receiving revenues of between R150- R250 a week. The logistic regression indicated that farmers already receiving some income from farming activities and those that had received training on hygienic farming practices were likely to wash hands and equipment prior to entering the field compared to those who had not. These variables influenced the hygienic practices with a probability of 26% and 32% respectively at 5% significance level. The logistic regression also showed that respondents with primary or no formal education were less likely to wash hands and equipment prior to entering the field compared to those who had a secondary level education. This unlikelihood had a probability of 35% for primary education and 43% for farmers with no formal education at significance levels of 5% and 10% respectively. This study indicates how training, education and farming experience are important and effective tools in implementing good hygienic practices in small-scale farming. The study’s main recommendations are that policies encourage farmer awareness on their responsibility of producing vegetables that are of good hygienic quality, especially if such produce is to reach the market. Furthermore policies should advocate for small-scale farmer training. This training should not be limited to subsistence farming but should also aim at preparing farmers towards accessing produce markets. Farmer training in hygienic practices should aid farmers to meet the stringent market standards allowing for better access, the regular income from such activities support farming as a livelihood and bearer of food security. It must also be noted that farmers require support in attaining the various resources needed in order to successfully and continually supply markets. / Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2013.

Magistrantūros studijų baigiamąjį darbą sudaro 48 psl., 2 lentelės, 20 paveikslų, 54 literatūros šaltiniai, 1 priedas, darbas parengtas lietuvių kalba. Tyrimo objektas – ekologiniai ir kiti ūkininkų ūkiai Kauno rajone. Tyrimo tikslas – išanalizuoti bei įvertinti darnaus ūkininkavimo reikšmę kraštovaizdžiui. Uždaviniai: 1. Išnagrinėti ir apibendrinti darnaus ūkininkavimo požymius; 2. Atskleisti kraštovaizdžio įtaką darniam ūkininkavimui; 3. Atlikti Kauno rajono ekologinių ir kitų ūkininkų ūkių darnaus ūkininkavimo reikšmės tyrimą kraštovaizdžiui. Darbe apibendrinti Lietuvos ir kitų šalių autorių moksliniai tyrimai, susijusieji su darnaus ūkininkavimo plėtros procesais, kurie skatina ekologinio ūkininkavimo perspektyvas ir saugo patį kraštovaizdį. Dėl ES pagalbos žemės ūkio sektoriui atsiranda įsipareigojimų, savo ūkius padaryti patrauklius, moderniai ūkininkaujant sumažinti neigiamą poveikį aplinkai ir tvarkytis taip, kad darnus ūkininkavimas natūraliai įsilietų į kraštovaizdį, nes stambėjant ūkininkų ūkiams dalinai nukenčia kraštovaizdis. Atlikus tyrimą nustatytas ryškus ekologinės žemdirbystės ūkių gausėjimas pereinamuoju laikotarpiu, 2010–2013 metais. Nors ekologinių ūkių skaičius pradėjo mažėti, tačiau sertifikuotas ekologinės gamybos plotas ir toliau auga. Tyrimo metu paaiškėjo, kad ūkininkai norėtų didesnių motyvuojančių išmokų efektyviai ekologinei gamybai (ūkis be paramos būtų nuostolingas). Taip pat jie pripažįsta, kad dėl darnaus ūkininkavimo gražėja kraštovaizdis... [toliau žr. visą tekstą] / Master‘s final work consists of 48 pages, including 2 tables, 20 pictures, 54 literature sources and 1 appendix. It was written in Lithuanian language. The object of the research – organic and other farmers‘ farms in Kaunas district. The aim of the research – to analyze and evaluate the significance of sustainable farming on the landscape. Tasks that were solved: 1. Features of the sustainable farming were analyzed and summarized; 2. The influence of the landscape upon sustainable farming was showed; 3. The research of the significance of the sustainable farming of organic and other farmers‘ farms of Kaunas district was carried out. In the work scientific researches related with the sustainable farming development processes were summarized, which stimulate organic farming and protect the landscape itself. Due to the EU's assistance to the agricultural sector liabilities occur to make farms attractive, to reduce the negative impact on the environment and manage in the way that sustainable farming naturally spilled into the landscape, as with the farmers’ farms getting bigger landscape is partially affected. The survey results show the significantly increasing number of farms of organic farming in the transition period of 2010-2013. Although the number of organic farms began to decline, the certified organic area continues to grow. The study revealed that farmers would like to receive larger motivating benefits for the efficient organic production. They also recognize that... [to full text]

Dans le contexte politique (réduction 50% de l’utilisation des pesticides à échéance de 2018 -Plan Ecophyto) et social actuel (mise en place de modes de production plus respectueux pour l'environnement), la sévérité des dommages causés par le puceron cendré du pommier, Dysaphis plantaginea Passerini (Hemiptera : Aphididae), surtout en agriculture biologique, rend nécessaire la mise au point de solutions alternatives s’appuyant sur le rôle des ennemis naturels. Nous avons donc essayé d’apporter des éléments nouveaux sur la connaissance des relations entre le puceron cendré et ses ennemis naturels et sur les conditions à même de favoriser leur action. Des suivis hebdomadaires des arthropodes présents sur les rameaux infestés par D. plantaginea, ont mis en évidence l’effet négatif des auxiliaires sur les populations de D. plantaginea, sans pour autant atteindre une véritable régulation à même d’éviter les dégâts économiques. Nous avons également montré l’action favorisante des fourmis sur la dynamique du puceron cendré et négative sur celle des auxiliaires. Nous avons pu identifier trois groupes d’auxiliaires dominants avec une arrivée séquentielle marquée : les syrphes, dont l’installation coïncide avec le début de l’infestation de D. plantaginea, puis les coccinelles et les forficules qui arrivent plus tardivement. Pour que les auxiliaires jouent un rôle plus important contre D. plantaginea, il faut d’autres pratiques permettant d’abaisser significativement le nombre de traitements pesticides. Une innovation très récente permet la réduction drastique des traitements insecticides : les filets Alt’Carpo. Malgré son influence négative sur l’abondance et la richesse du cortège des auxiliaires présents dans les colonies de D. plantaginea, surtout les coccinelles, cette technique freine le développement des populations de D. plantaginea à l’échelle du rameau ou de l’arbre lorsque les filets sont fermés après la floraison (en conformité avec les préconisations contre le carpocapse). Cependant, la réduction des populations de D. plantaginea sous les filets requiert la présence d’au moins un stade actif d’auxiliaire par rameau, ce qui interroge sur la réalité de la régulation de ce ravageur par le simple usage des filets. Sur la base de leur précocité, pour Episyrphus balteatus De Geer (Diptera : Syrphidae) et de leur abondance dans les colonies de D. plantaginea, pour Forficula auricularia Linnaeus (Dermaptera : Forficulidae) et E. balteatus, ces deux espèces apparaissent comme de bons candidats pour la régulation de D. plantaginea. Nos études en conditions contrôlées ont démontré leur potentiel régulateur sur D. plantaginea, en particulier aux stades les plus âgés. L’efficacité optimale intervient à 20°C pour les deux prédateurs, pour lesquels nous n’observons par ailleurs pas d’interaction négative lorsqu’ils sont associés en présence de fortes densités de D. plantaginea. Sur la base de ces résultats de laboratoire nous avons analysé les possibilités de lâchers printaniers de ces deux prédateurs sur de jeunes colonies de D. plantaginea. Dans nos conditions expérimentales en vergers de pommiers, des lâchers précoces de larves du 3ème stade de F. auricularia n’ont pas permis de limiter les populations de D. plantaginea, confirmant la difficulté des lâchers de prédateurs en cultures de plein champ. De la même manière, des lâchers précoces d’E. balteatus pourtant réalisés sous filets Alt’Carpo restent sans effet sur l’infestation par D. plantaginea. Cette thèse, en s’appuyant sur des essais en conditions contrôlées, semi contrôlées et de plein champ, constitue une étape dans un processus d’élaboration d’un modèle dynamique du développement de D. plantaginea à l’échelle du rameau, prenant en compte le rôle des fourmis et des auxiliaires et l’influence des pratiques de protection (par exemple, les filets Alt’Carpo et les lâchers d’auxiliaires). Elle confirme, si besoin en était, la complexité des phénomènes de régulation, des pucerons en particulier, et la nécessité d’études complémentaires pour définir les conditions d’application de la lutte biologique contre D. plantaginea / In the current political and social context (reduced use of pesticides), there is a need for the development of alternative solutions to control the rosy apple aphid, Dysaphis plantaginea Passerini (Hemiptera : Aphididae), especially in organic farming. One of these alternatives is the increased and improved use of natural enemies against this pest. In this thesis, we provided some elements of responses regarding this problem in term of research study and technical application. Based on weekly observations of arthropods in marked shoots infested by D. plantaginea, we demonstrated the negative effects of the natural enemies on the development of D. plantaginea but this effect was unsufficient to provide an effective regulation avoiding economic damages. We also showed the possible and positive influence of ant presence on the infestation dynamics and thei rnegative effect on natural enemies. Among the natural enemy groups, three were the most abundant and appeared in a temporary sequence : syrphids arrived first, at the beginning of the infestation,followed by coccinellids and earwigs that arrived later.To enhance the role of the natural enemies against D. plantaginea, we also need other practices that enable to reduce significantly the number of pesticide applied. This is the case of a very recent innovation : the Alt'Carpo nets. Despite its negative influence on the abundance and richness of the natural enemies, especially the coccinellids, present in the colonies of D. plantaginea, there was a negative influence of these nets on the development of D. plantaginea populations (both at the shootand tree levels) especially when the nets were closed in mid-April (coinciding with classical netting trees for controlling populations of codling moth). We additionally showed that the highest reductionin D. plantaginea population was observed in the presence of at least one active natural enemy in the marked shoot. This gives support to the combination of these methods of control, one biological and the other physical, to regulate D. plantaginea populations. Based on their precocity for Episyrphus balteatus De Geer (Diptera : Syrphidae) and their abundance for both Forficula auricularia Linnaeus (Dermaptera : Forficulidae) and E.balteatus observed under field conditions, the syrphids and earwigs appear as good candidates for controlling the D. plantaginea populations. We first demonstrated under laboratory conditions using detached plantain leaves in Petri dishes conditions the potency of these two predators, especially a tolder stages, against D plantaginea. The optimal predation occurred at 20°C for both predators. Using young apple trees, we further studied the possible interactions between these predators and showed a small and positive interaction when the D. plantaginea density was not limiting. But at low densities of aphids, the results suggested a possible negative interaction (a sign of intraguild predation) between these two predators. These results from laboratory studies have led us to study the augmentative release of these two predators, under field conditions, in early spring for controlling D. plantaginea populations. The releases of F. auricularia (third instar nymph) did not result in lower D. plantaginea populations. This confirmed the difficulty of successful releases of natural enemies under theconditions of open orchards, and demonstrated the need for improving or creating conditions that canpromote the success of the released natural enemies. However, despite closed conditions, the early release of E. balteatus under Alt'Carpo nets was also not efficient against D. plantaginea.This thesis, through several studies under different conditions (controlled, semi-field and field), represented an important first step that should ideally lead to the development of a dynamic model of the development of D. plantaginea at the shoot level, taking into account the presence of ants and therole of natural enemies and the influence of some agricultural practices (for example Alt'Carpo nets and natural enemy releases). Further studies are also needed to validate our results (effects of Alt'Carpo nets) and to optimise the releases of natural enemies

A crescente necessidade de alimentos objetivando a satisfação da nutrição animal em sistemas orgânicos, aliado ao recente mercado mundial desse tipo de produtos, tem suscitado a elevada preocupação com o aperfeiçoamento de sistemas orgânicos, incluindo a produção de milho. Assim, neste contexto, foi realizado no município de Piracicaba, SP, Brasil, em área pertencente à Escola Superior de Agricultura Luiz de Queiroz/Universidade de São Paulo, um experimento de campo objetivando a avaliação do desempenho e produtividade de milho consorciado a adubos verdes, em sistema orgânico de produção. Para tanto, foram utilizados dois genótipos, um híbrido (Pioneer 30P70) e uma variedade (BRS4157 Sol-da-manhã), consorciados a duas espécies de adubos verdes (Crotalaria juncea e Canavalia ensiformis) e submetidos a doses crescentes de nitrogênio, mediante o uso de farinha de chifre, perfazendo o total de 18 tratamentos e 3 repetições. O delineamento adotado foi o esquema fatorial 3X9, em blocos ao acaso, envolvendo a interação de genótipos, adubos verdes e doses de nitrogênio. A análise dos resultados, permitiu concluir que: a)o híbrido Pioneer 30P70 é mais produtivo e apropriado para sistemas orgânicos de produção, com o uso de fontes de nitrogênio, em comparação à variedade Sol-da-manhã; b)A variedade Sol-da-manhã não responde satisfatoriamente ao emprego de doses crescentes de nitrogênio, representadas pelo uso de farinha de chifre;c)A farinha de chifre não contribui, de forma imediata, para a elevação dos teores de nitrogênio nas plantas de milho, até os níveis considerados adequados para a espécie; d)Sistemas consorciados de milho com crotalaria (Crotalaria juncea) ou feijão-de-porco (Canavalia ensiformis) não afetam a produtividade do mencionado cereal e e) As espécies de adubos verdes avaliadas não contribuem significativamente para o aporte de nitrogênio às plantas de milho a eles associadas, durante o ciclo vital do referido cereal. / The increasing need for feed to fulfill animal nutritional requirements in organic systems, besides the increasing world demand for organic products, has raised a concern about the improvement of organic systems, including maize production. Within this context, an experiment aiming at evaluating the performance and yield of corn intercropped with green manures in an organic production system was carried out in Piracicaba, SP, Brazil at the Escola Superior de Agricultura Luiz de Queiroz / University of Sao Paulo. Two maize genotypes were tested, a hybrid (Pioneer 30P70) and a variety (BRS4157 Sol-da-manhã), both intercropped with two green manure species (Crotalaria juncea and Canavalia ensiformis) and submitted to increasing N doses by horn meal, adding up to 18 treatments and 3 replicates. The plot design was factorial 3x9, in randomized blocks involving the genotypes interaction, the green manures and nitrogen doses. The results analysis allowed the following conclusions: a) When fertilized with N sources, the hybrid Pioneer 30P70 is more productive and more suitable for organic systems compared to the variety Sol-da-manhã; b) the variety Sol-da-manhã does not have a response to increasing N fertilization; c) the horn meal does not contributes immediately to the increasing amount of N in maize plants up to the nutritional level suitable for the species; d) the intercropping systems between maize and sun hemp (Crotalaria juncea) or jack bean (Canavalia ensiformis) do not affect the cereal yield and e) the evaluated green manures species do not significantly contribute with the N supply of the associated maize plants during its life cycle.

Agricultores e técnicos envolvidos na citricultura orgânica procuram desenvolver sistemas de produção com maior atividade microbiana no solo. Dessa maneira, esperam obter benefícios dos processos que ocorrem no solo, entre eles, o controle natural de pragas e doenças. Porém, são poucos os estudos sobre a influência desse tipo de manejo sobre a microbiota do solo, em especial sobre os fungos micorrízicos arbusculares (FMAs) e o patógeno Phytophthora parasitica. Os objetivos dessa tese foram: avaliar a colonização micorrízica e conhecer a diversidade de FMAs nos sistemas de produção convencional e orgânico de citros; avaliar a aplicação de benomyl e da radiação &#947; na obtenção de testemunhas não micorrizadas para estudo de interação de comunidade de FMAs nativos e P. parasitica; verificar a capacidade indutora de resistência local e sistêmica dos FMAs nativos a P. parasitica; estudar atividade da quitinase no sistema radicular de limão 'Cravo' colonizado por fungos micorrízicos nativos. Foram realizadas amostragens em dois sistemas de produção de citros em São Paulo, um convencional e um orgânico. A riqueza e a diversidade de espécies de FMAs foram maiores no manejo orgânico. No entanto, a porcentagem de colonização micorrízica nas plantas no campo não variou com o tipo de manejo. Em casa de vegetação, experimentos com plantas de limão 'Cravo' (Citrus limonia) mostraram que a radiação &#947; foi mais adequada que a aplicação de benomyl na obtenção de testemunhas não micorrizadas para estudo de interação P. parasitica- FMAs nativos de agroecossistemas de produção de laranja. Também em casa de vegetação, foi realizado um experimento com raiz dividida de plantas de limão 'Cravo'. Não foi possível avaliar a capacidade indutora de resistência dos fungos micorrízicos arbusculares nativos porque não houve desenvolvimento da podridão de raízes nas plantas de limão 'Cravo' após a infestação com P. parasitica. Discute-se a interação de patógenos de raiz do solo natural e os FMAs nativos porque o solo natural dos sistemas de produção convencional e orgânico promoveram diferentes respostas de crescimento local e sistêmico das raízes das plantas micorrizadas. A atividade de quitinase foi igual nas raízes de plantas micorrizadas e não micorrrizadas cultivadas em solos dos sistemas de produção convencional e orgânico. Porém, a associação micorrízica aumentou localmente a proteína total nas raízes das plantas. / Farmers and technicians involved with organic citriculture try to develop systems with high microbial activity in soil. In this way, they expect to obtain benefits from processes that occur in soil, as natural control of pests and diseases. However, there are few studies about the influence of this type of management on soil microbiota, specially on the arbuscular mycorrhizal fungi (AMF) and the pathogen Phytophthora parasitica. The objectives of this thesis were: to evaluate mycorrhizal colonization and diversity of AMF in citrus conventional and organic farming; to evaluate benomyl application and &#947; radiation to obtain non-mycorrhizal controls for study of interaction between indigenous AMF and P. parasitica; to verify local and systemic capacity of indigenous AMF to induce resistance against P. parasitica; to study chitinase activity in roots of 'Rangpur' lime colonized by indigenous AMF. Samplings were carried out in two citrus systems in São Paulo, one conventional and one organic farming. The richness and the diversity of AMF species were higher in the organic farming. In greenhouse, experiments with 'Rangpur' lime (Citrus limonia) showed that &#947; radiation was better than benomyl to obtain non-mycorrhizal control for studies of interaction between P. parasitica-indigenous AMF from orange agroecosystems. In greenhouse also, a split root experiment with 'Rangpur' lime was carried out. It was not possible to evaluate the indigenous AMF capacity to induce resistance because no root rot developed in 'Rangpur' lime plants after inoculation with P. parasitica. We discuss the interaction between root pathogens in natural soil and indigenous AMF because natural soil from conventional e organic farming promoted different local and systemic root growth responses in mycorrhizal plants. Chitinase activity was similar in roots of mycorrhizal and non-mycorrhizal plants grown in conventional and organic farming soils. However, mycorhizal association increased local protein content in roots.

Made available in DSpace on 2017-07-21T18:53:05Z (GMT). No. of bitstreams: 1 Tiago Margraf.pdf: 3444633 bytes, checksum: 00ddc78a605b890f5109af10a0c0c5e6 (MD5) Previous issue date: 2015-11-12 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Worldwide, the consumption of purple grape juice has grown since several studies point to the potential health benefits, combined with a balanced diet and regular physical exercise. These potential benefits are related to the bioactive compounds present in this fruit and other plants, responsible for the inhibition of reactive oxygen and nitrogen species, formed in oxidative and inflammatory processes in the human body. In this context, researchers have tried and tested fast, inexpensive, accurate and reproducible methods, which are able estimating the content of bioactive compounds in beverages and foods. In this scenario, the objectives of this study were divided in two experimental chapters, where the Chapter II had as purpose to test and validate a more selective spectrophotometric method than the Folin-Ciocalteu assay, to quantify the content of phenolic compounds in grape juice. Already the Chapter III had as purpose to characterize n = 62 juices Brazilian purple grapes from different geographic origins (RS, PR and SC), agronomic (organic and conventional) and genotypic (Bordo, Isabel and Concord) about its physicochemical and chemical properties, and in vitro antioxidant activity using chemical and biological systems. The results showed that the Prussian Blue method has low detection (0.27 mg L-1) and quantification limit (0.92 mg L-1), and a high association (r = 0.923, p < 0.0001) with the standard method of Folin-Ciocalteu reagent for the grape juice matrix, and also a faster reaction and high selectivity compared to the Folin-Ciocalteu assay. Furthermore, the geographical origin and the grape variety proved to be the most important factors in distinguishing juices (p < 0.05) for antioxidant activity and some chemical markers. However for the organic and conventional juices, except for some phenolic acids determined by high-performance liquid chromatography, there were no statistically significant distinctions (p > 0.05). A total of n = 18 grape juices were characterized by presenting high, intermediate and low antioxidant activity in vitro using four different methodologies (Scavenging of ABTS●+ radical; Ferric-reducing antioxidant power - FRAP; Total reducing power; and Reducing potential of the hydrophilic phenolic compounds - RPHPC) and were subjected to analysis of the inhibition of lipid peroxidation at 37 °C by means of a biological assay in buffered medium at pH 7.4. The inhibition of lipid peroxidation of the grape juice showed a significant correlation (r ≥ 0.505; p ≤ 0.02) with other antioxidant activity assays, concluding that the antioxidant activity in vitro of Brazilian purple grape juice has association either by chemical methods or by biological means. / Em todo o mundo, o consumo de sucos de uva roxa tem crescido, visto que vários estudos apontam os potenciais benefícios à saúde, aliados a uma alimentação equilibrada e a prática regular de exercícios físicos. Esses potenciais benefícios estão relacionados com os compostos bioativos presentes nesta fruta e em demais vegetais, responsáveis pela inibição de espécies reativas de oxigênio e nitrogênio, formadas em processos oxidativos e inflamatórios no corpo humano. Nesse contexto, pesquisadores têm testado e validado metodologias rápidas, baratas, precisas e reprodutíveis, que possibilitem estimar o conteúdo de compostos bioativos em bebidas e alimentos. Nesse cenário, os objetivos deste estudo foram divididos em dois capítulos experimentais, dos quais o Capítulo II objetivou testar e validar uma metodologia espectrofotométrica mais seletiva que o Folin-Ciocalteu para quantificar o teor de compostos fenólicos totais em suco de uva. Já no Capítulo III, objetivou-se caracterizar n=62 sucos de uvas roxas brasileiros de diferentes origens geográficas (RS, PR, e SC), agronômicas (orgânicos e convencionais), e genotípicas (Bordô, Isabel, e Concord) quanto às suas propriedades físico-químicas, químicas, e atividade antioxidante in vitro usando sistemas químicos e biológico. Os resultados mostraram que o método do Azul da Prússia apresentou um baixo limite de detecção (0,27 mg L-1) e quantificação (0,92 mg L-1), e uma alta associação (r = 0,923; p<0,0001) com o método padrão de Folin-Ciocalteu para a matriz de suco de uva, além de menor tempo de reação e alta seletividade comparado ao ensaio de Folin-Ciocalteu. A origem geográfica e a variedade de uva mostraram-se os fatores mais importantes na distinção dos sucos (p<0,05) para atividade antioxidante e alguns marcadores químicos. Já para os sucos orgânicos e convencionais, com exceção para alguns ácidos fenólicos determinados por cromatografia líquida de alta eficiência, não foram encontradas distinções estatisticamente significativas (p>0,05). Um total de n=18 sucos de uva foram caracterizados por apresentarem alta, intermediária e baixa atividade antioxidante in vitro usando quatro metodologias diferentes (Seqüestro de radicais ABTS●+; Poder antioxidante de redução do ferro - FRAP; Poder redutor total; Potencial redutor dos compostos fenólicos hidrofílicos - PRCFH) e foram sujeitados à análise de inibição da peroxidação lipídica a 37 oC por meio de um ensaio biológico em meio tamponado em pH 7,4. A inibição da peroxidação lipídica dos sucos de uva apresentou uma correlação significativa (r ≥ 0,505; p ≤ 0,02) com outros ensaios de atividade antioxidante, concluindo-se que a atividade antioxidante in vitro de suco de uva roxa brasileiro apresenta associação tanto por métodos químico quanto em meio biológico. Palavras-chave: cultivo orgânico, peroxidação lipídica, capacidade redutora, análise multivariada, Vitis sp.

L'activité agricole peut entraîner un déséquilibre des cycles du carbone (C) et de l'azote (N) dans les écosystèmes terrestres naturels et entrainer une diminution des stocks de C et N dans le sol, une augmentation de la lixiviation du nitrate et des pertes d'azote par voie gazeuse. Pour réduire ces impacts environnementaux, la mise en place de systèmes agricoles innovants et durables est encouragée, tels que les systèmes à bas niveau intrants, l'agriculture de conservation ou l'agriculture biologique. Les objectifs de cette thèse sont i) de quantifier l'impact à long terme des différents systèmes de culture sur le devenir du carbone et de l'azote dans le système sol-plante-atmosphère et ii) de simuler la dynamique de ces éléments avec le modèle agro-environnemental STICS. À cette fin, nous avons étudié trois essais de longue durée : l'essai de La Cage (France) établi en 1998, l'essai DOK (Suisse) débuté en 1978 et l'essai Foulum (Danemark) créé en 1998. Alors que l'essai de La Cage a permis une quantification in situ du stockage du carbone et de l'azote organiques du sol, de la lixiviation de l'azote, des émissions de protoxyde d’azote (N2O) et de la balance des gaz à effet de serre pour des systèmes de culture alternatifs, les essais danois et suisses ont permis l'estimation in silico du devenir du C et N en agriculture biologique, après adaptation du modèle STICS pour simuler de nouvelles pratiques culturales. Après 16 années d’expérimentation, une accumulation annuelle significative de SOC et de SON a été observée en agriculture et en agriculture biologique à La Cage, alors qu'aucun changement significatif n'a été observé dans les systèmes conventionnels et bas intrants. La minéralisation spécifique de SOC et SON des quatre systèmes, simulée sur AMG et mesurée lors d’incubation des sols pendant quatre mois, s’est montrée équivalente entre systèmes. Le stockage de C et N observé dans les systèmes de conservation et biologiques s’explique principalement par l'augmentation des résidus de cultures plutôt que par l'effet du non-labour en agriculture de conservation. De plus, le surplus azoté (différence entre apports et exportations d’azote) a été calculé pour chaque système de culture. Le devenir de l’excédent d’azote a été estimé entre stockage de N dans le sol, pertes gazeuses et lixiviation de l'azote. Les émissions cumulatives de N2O mesurées en continu pendant plus de trois ans sont fortement corrélées avec les pertes totales calculées de N par voix gazeuse (volatilisation et dénitrification), ces pertes étant les plus importantes dans le système de conservation. Enfin, la réalisation d’un bilan complet des émissions de GES a montré de fortes différences entre système et des phénomènes de compensation entre stockage et perte de C et N. Le modèle sol-culture STICS a ensuite été utilisé pour simuler le devenir de l’azote dans les essais DOK et Foulum. Après une adaptation du modèle, sa calibration et son évaluation ont été réalisées permettant de simuler de façon satisfaisante les rendements, l'absorption de N, le surplus de N et l’évolution des stocks de SON dans les systèmes conventionnels et biologiques. Les simulations suggèrent que le devenir de l’azote dans ces systèmes peut être contrasté en fonction de la fertilisation et de la gestion des cultures et que les pertes d'azote ne sont pas systématiquement réduites en agriculture biologique par rapport au conventionnel. Cette thèse remet en question les appréciations simplistes qui associent systématiquement systèmes de culture alternatifs et diminution des impacts environnementaux liés aux cycles de C et N / Agricultural activities can lead to imbalanced carbon (C) and nitrogen (N) dynamics compared to natural terrestrial eco-systems, causing potential damages for soil, water and air quality. Among these prejudices, decreased soil C and N stocks, increased nitrate leaching in waters and gaseous N emissions towards the atmosphere are of a major concern. To reduce these environmental impacts, innovative and sustainable farming systems are promoted, such as low inputs cropping systems, “conservation” agriculture or organic farming. The objectives of this work were i) to quantify the long term impact of different alternative cropping systems on the fate of C and N in the soil-plantatmosphere system and ii) to simulate C and N dynamics with the agro-environmental model STICS. For this purpose, we studied three long-term field trials: the experiment of La Cage (France) established in 1998, the DOK (Switzerland) started in 1978 and the Foulum Organic (Denmark) established in 1998. The methodological approach combined experimentation and modelling. While La Cage trial enabled an in situ quantification of soil organic C and N storage, N leaching, nitrous oxide (N2O) emissions and greenhouse gas (GHG) balance in alternative cropping systems compared to conventional, the Swiss and Danish experiments were used for in silico estimation of the C and N fates in organic cropping systems, after adaptation of the STICS model, followed by calibration and evaluation of the model. Significant annual SOC and SON accumulation was found under conservation agriculture and organic farming at La Cage, whereas no significant change was observed in the low input and the conventional systems. No difference of specific SOC and SON mineralization rates was found between systems in vitro or in silico : we conclude that the higher C and N storage in soil observed in the conservation and organic systems was mainly driven by increased crop residues, rather than by the effect of no tillage practiced in conservation agriculture. The N surplus, i.e. the difference between N inputs and N exports at the field scale, varied widely between treatments. The fate of this N surplus also varied between systems with wide variations in SON storage and gaseous losses but no differences in N leaching. The cumulative N2O emissions measured continuously for three years were highly correlated with the calculated gaseous N losses (volatilization and denitrification), with higher losses in the conservation system. These calculations allowed establishing a full GHG balance. Therefore the four agricultural systems dissimilarly impacted the N fate, which could not be predicted by the N surplus alone. The GHG balance is a much better indicator of the environmental impact of cropping systems relative to C and N fluxes. In the Danish and Swiss experiments, the soil-crop model STICS was used to mimic crop production, N uptake and N surplus. The model was first adapted and evaluated to simulate organic farming systems. The model could satisfactorily simulate crop production, N uptake, N surplus and SON storage in the organic and conventional systems of these two longterm experiments. Model outputs suggested that the N fate could be contrasted according to fertilization and crop management, and that N losses were not systematically reduced in organic compared to conventional cropping systems. This study challenges the frequent belief that alternative cropping systems systematically improve the global C and N environmental impacts of agriculture.

Made available in DSpace on 2014-12-17T15:38:39Z (GMT). No. of bitstreams: 1 YldrySRQP_TESE.pdf: 1712079 bytes, checksum: b17d9a120b94e31c6978b40928b45ad1 (MD5) Previous issue date: 2014-03-13 / Universidade Federal do Rio Grande do Norte / Knowledge of quality of life is a very complex and rich in cultural and subjective dimensions, understood in a broad sense and multivariate theme. Considering the rural areas from agriculture, it is observed that the production standard defines significant changes in the environmental context and the quality of life of rural workers. To explain the relationship between quality of life and Family Organic Agriculture, we sought to analyze the quality of life of the organic family farmer, after change in agricultural management. The research, based on a procedure exploratory study supported the articulation theoretically constructed, showed their relevance and allowed to delimit with greater security, the central question of work. The WHOQOL - 100 treated the instrument of research on quality of life that directed the field study with organic farmers from the town of Lagoa Seca / PB. Farmers and family members are from rural regions Almeida, Alvinho, Lagoa de Barro, Lagoa Gravat?, Oiti and Pau Ferro. The average time is 39 years farming and organic family farm is 16 years. In the analysis work was found that the process of production of vegetables and fruits is divided into 08 steps and with respect to workloads observations showed the presence of: physical loads, mechanical stresses, psychological burden and ergonomic factors. Most farmers reported symptoms were fatigue and cramps in the legs . Regarding the quality of life was noticed that the Psychological Domain contributed positively to the quality of life with mean and standard deviation (17.83 ? 12.78) and Domain Environment negatively contributing to the quality of life of this group (9.00 ? 6.82). We conclude that the practice of Family Organic Agriculture should be seen as an effective strategy in promoting quality of life and social values in between, since it presents environmental sustainability with regard to life and socio-cultural diversity of populations / O conhecimento de qualidade de vida ? um tema muito complexo e rico em dimens?es subjetivas e culturais, entendidas em uma percep??o vasta e multivariada. Considerando o meio rural a partir da agricultura, observa-se que o padr?o produtivo define modifica??es expressivas no contexto ambiental e na qualidade de vida dos trabalhadores rurais. Para explanar a rela??o entre qualidade de vida e Agricultura Familiar Org?nica, buscou-se analisar a qualidade de vida do agricultor familiar org?nico, ap?s mudan?a no manejo agr?cola. A investiga??o, baseada em um procedimento de estudo explorat?rio, apoiou a articula??o constru?da teoricamente, mostrou sua pertin?ncia e permitiu delimitar, com maior seguran?a, a quest?o central do trabalho. O WHOQOL-100 tratou-se do instrumento de pesquisa sobre qualidade de vida que direcionou o estudo de campo com os agricultores familiares org?nicos da cidade de Lagoa Seca/PB. Os agricultores e membros da fam?lia s?o oriundos das regi?es rurais Almeida, Alvinho, Lagoa de Barro, Lagoa Gravat?, Oiti e Pau Ferro. O tempo m?dio de agricultura ? de 39 anos e na agricultura familiar org?nica ? de 16 anos. Na an?lise do trabalho se verificou que o processo de produ??o de verduras e frutas se divide em 08 etapas e em rela??o ?s cargas de trabalho as observa??es mostraram a presen?a de: cargas f?sicas, cargas mec?nicas, carga psicol?gica e cargas ergon?micas. Os sintomas mais referidos pelos agricultores foram c?imbras e fadiga nas pernas. No que concerne ? qualidade de vida percebeu-se que o Dom?nio Psicol?gico contribuiu positivamente para a Qualidade de Vida com m?dia e desvio (17,83?12,78) e o Dom?nio Ambiente contribuindo negativamente para a Qualidade de Vida deste grupo (9,00?6,82). Conclui-se que a pr?tica da Agricultura Familiar Org?nica deve ser vista como uma estrat?gia eficaz na promo??o da qualidade de vida e de valores sociais nesse meio, uma vez que apresenta sustentabilidade socioambiental que respeita a vida e a diversidade sociocultural das popula??es

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