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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

THE EFFICACY OF COVER CROPS FOR POLLINATOR HABITAT PROVISION AND WEED SUPPRESSION IN A SOUTHERN ILLINOIS AGROECOSYSTEM

Bryan, Casey J. 01 May 2019 (has links)
Increases in agricultural intensification over the past century have resulted in significant alterations to the rural landscape across the Midwest. Pollinators are essential to sustain natural and managed ecosystems. They are vital for food production and their declines have been linked, in part, to a rise in intensive agricultural practices. There is a recognized need among numerous stakeholders to build sustainability into the management of agroecosystems to protect both the biotic and abiotic resources of these systems. The use of cover crops is gaining interest among agricultural producers for benefits such as improving water quality and soil health. Cover cropping systems have the potential to provide floral resources to pollinators and suppress problematic driver weeds. The overall objective of this study was to quantify the effects of cover crops on plant and pollinator biodiversity within agricultural systems. This study aimed to characterize the pollinator diversity indicative of the patchwork mosaic forest-agroecosystem of Crab Orchard National Wildlife Refuge; evaluate the roles cover crop treatments play in supporting pollinator diversity and weed suppression benefits in a conventionally managed system; and provide the basis of recommendations for sustainable weed suppression tactics and for enhancing the quality of pollinator habitat within agricultural systems.
2

An agronomic and social perspective of industrial hemp adoption by organic farmers in the Midwest

Leah N. Sandler (5930222) 10 June 2019 (has links)
<p>Hemp (Cannabis sativa L.) is an annual crop used to produce a wide range of products including foods, beverages, nutritional supplements, fabrics, and textiles. Hemp has long been conflated with marijuana and has not been grown in the United States for decades. Due to recent legislation, the legal restrictions on growing hemp seem likely to be lifted. However, although interest is high, industrial hemp has not been grown in the U.S. for nearly 80 years and research on virtually all aspects of hemp production in the U.S. is in its infancy. We lack fundamental knowledge regarding cultivar performance, interactions with pests, particularly weeds, and nutrient requirements. Research is needed to address this knowledge gap and potential production issues as well as to determine the attitudes, perceptions and concerns of farmers regarding the potential adoption of this “new” crop. Importantly, research should be conducted before the crop becomes widely available so that farmers can make informed decisions and avoid costly mistakes. My dissertation consists of four chapters. In Chapter 1, I examine the literature for weed management in hemp production and identify research gaps. In Chapter 2, I investigate the complex legal framework that surrounds Cannabisand the resulting complications for hemp production. In Chapter 3, I present research conducted to determine the attitudes, perceptions, interests and concerns of organic farmers regarding the reintroduction and potential adoption of hemp was completed through survey research. Finally, in the fourth chapter, I present research conducted to characterize the growth and phenology of industrial hemp cultivars and identify cultivars suitable for growing conditions in the Midwest, and to determine the effect of delayed planting on the phenology and growth of seed and fiber hemp varieties in the Midwest.</p><p>Weed control and weed management in industrial hemp production is a surprisingly understudied field. Few peer-reviewed field studies on hemp exist on any subject and in particular, weed control and weed management is understudied. Specifically, only three studies designed to address a weed management issues exist in the literature dating back to 1900. Most commodity crops have extensive literature discussing weed management, and such an extensive gap in the hemp literature suggests that research needs to be conducted to determine the impacts of weeds on hemp production. Discrepancies among state laws and current federal drug legislation have created a convoluted, confusing, and impractical framework currently surrounds hemp production in the U.S. The building of pesticide regulation and product safety systems that are specific to the many end uses of Cannabis have yet to occur in the U.S. Interactions between producers, state and federal government, and third-party testing laboratories need to be facilitated to build regulation systems along with educational programs to train growers appropriate best management. Organic farmers are generally considered less risk adverse than the general farming population and often considered early adopters of technology. I surveyed organic farmers in seven Midwestern states and found that 98.5% of the respondents were generally open to new technologies, but that demographics variables explained little of the variation for respondents’ level of innovativeness as well as their openness to hemp.The respondents were generally open to hemp production (88.2% agreed with the statement that they were open to trying hemp production on their farm) and found that attributes of hemp production that conferred relative advantage and were compatible with existing systems were important. Delayed planting of hemp generally reduced the onset and duration of female flowering and the time to seed formation but the magnitude of these effects varied among cultivars. Seed, stalk, and total above ground dry weight yields varied across cultivar and planting date which may have been impacted by inconsistent stand densities stemming from heavy rainfall and wet soils. Results from this dissertation suggest that hemp is an understudied crop in the U.S., but that interest in its production among organic farmers exists. Field results support the importance of both planting date and cultivar for hemp phenology discussed in previous literature and so research needs to be conducted to explore best hemp production practices in the U.S.<br></p><p></p>
3

Diversité fonctionnelle des rhizobia associés à la féverole en agro-écosystème Sud de France / Functional diversity of Faba-bean associated rhizobia in agro-ecosystem of South of France

Domergue, Odile 19 December 2017 (has links)
L’aptitude des symbioses rhizobium-légumineuses à fixer l’azote atmosphérique, peut offrir d’importants services aux agro-écosystèmes. Cependant, associés à des contraintes biotiques (i) absence et/ou (ii) inefficacité symbiotique des rhizobiums du sol, des facteurs abiotiques (i) excès d’intrants azotés et/ou (ii) carences en phosphore (P) peuvent limiter la fixation symbiotique d’azote (FSN). Le Myo-inositol hexakisphosphate (phytate), principale composante de P organique (Po) du sol, représente une potentielle source de P disponible du sol, bio-disponible pour la plante, en lien à des activités phytases microbiennes, minéralisatrices du phytate. Afin de rechercher des rhizobiums, symbiontes de Vicia faba, efficaces dans l’utilisation du P (EUP) pour la FSN, nous avons réalisé un diagnostic nodulaire multilocalisé, en agro-écosystèmes sud de France. Le niveau d’efficacité d’utilisation de la symbiose rhizobienne (EUSR), en intra- et inter-placettes agricoles et en conditions hydroaéroponiques en serre, a été déterminé en corrélation des biomasses aériennes et nodulaires de plants de V. faba, à floraison. Parmi 59 isolats de V. faba, 26 sont aptes à minéraliser le phytate (Phy +), en milieu solide et six d'entre eux confirment une activité phytase, en culture liquide. L’intérêt d’une sélection de rhizobiums locaux aptes à une EUP pour FSN, nous a conduits à une avancée dans la sélection de marqueurs moléculaires phytases pour le criblage d’isolats rhizobiens Phy+. Mots ClésRhizobium, diversité, phytase, féverole, Vicia faba, nodulation, France-sud, agro-écosystème. / The ability of rhizobium-legume symbiosis to fix atmospheric nitrogen can provide important services to agro-ecosystems. However, associated with biotic constraints (i) missing and/or (ii) phosphorus (P) deficiency, can limit symbiotic nitrogen fixation (SNF). Myo-inositol hexakisphosphate (phytate), the main soil organic P (Po) component, represents a potential source of soil P available for plant P bio-availability, connected with microbial phytate-mineralizing activities. In order to look for rhizobium-Vicia faba, in P use efficiency (PUE) for SNF ability, nodular diagnosis was performed from a multi-location survey in an agro-ecosystem in South France. The efficiency in use of rhizobial symbiosis (EURS) was deduced from V. faba nodule and shoot dry weight values at flowering state, and compared in intra- and inter agricultural fields and in greenhouse hydroaeroponic conditions. Among 59 V. faba isolates, 26 were able to mineralize phytate (Phy+) in solid medium and six of them confirmed phytase activity in liquid culture. Looking for local rhizobiums with PUE for SNF ability, led us to a forward step in molecular marker selection for Phy+ rhizobium isolate screening. KeywordsRhizobium, diversity, phytase, faba-bean, Vicia faba, nodulation, South-France, agro-ecosystem.
4

Ciclos biogeoquímicos como subsídio para a sustentabilidade do sistema agroindustrial da cana-de açúcar

Barbosa, Valmir [UNESP] 01 June 2007 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-06-01Bitstream added on 2014-06-13T19:58:03Z : No. of bitstreams: 1 barbosa_v_me_jabo.pdf: 1888989 bytes, checksum: 65cff8d303405177db46baa69842eb27 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Usina Acucareira Corona / O crescimento da cultura da cana-de-açúcar, frente à demanda global por energia renovável, provoca preocupações quanto à sua sustentabilidade. Nesse contexto, o objetivo deste trabalho é oferecer uma visão sistêmica do processo agroindustrial da cana-de-açúcar, do ponto de vista dos ciclos biogeoquímicos com a reciclagem de resíduos e efluentes. Para o desenvolvimento do trabalho foram elaborados modelos conceituais e numéricos, apresentando conceitos de ruptura e regeneração de ciclos, sustentabilidade cruzada, equação de configuração do canavial e coeficiente de uso cultural da terra. Foi elaborado um modelo das vias e de estratégias de uso de resíduos e efluentes para N, P, K, Ca, Mg e S, nos diversos compartimentos do processo de produção. Fez-se uma abordagem sobre metais pesados. Foram formulados e discutidos alguns indicadores: índice de adubação (IA), índice de retorno (IR) e índice de emissão (IE), que permitiram uma análise da circulação de nutrientes e da sustentabilidade. No cenário analisado para validação do modelo, concluiu-se que as quantidades de potássio, cálcio e magnésio em circulação foram suficientes para a adubação da cultura, enquanto o nitrogênio, fósforo e enxofre emitidos foram insuficientes, exigindo adubações complementares. Concluiu-se que a moderna agroindústria da cana-de-açúcar apresenta-se conceitualmente muito favorável à sustentabilidade, e ainda exige melhorias para a efetividade desses conceitos. A verticalização da produção, mesmo em monocultivo, pode contribuir para o estabelecimento de um equilíbrio de manejo favorável à sustentabilidade. / The expansion of the sugarcane culture, up against global demand for renewable energy, provokes concerns as for its sustainability. In this context, the objective of this work was to offer a systemic view of the sugarcane agro-industrial process, from the point of view of the biogeochemical cycles with the effluent and residues recycling. For the development of the work conceptual and numerical models were elaborated, showing concepts of rupture and regeneration of cycles, crossed sustainability, cane field configuration equation and cultural land use coefficient. A model of the logistics and use strategies of effluent and residues for N, P, K, Ca, Mg and S was elaborated, in the several compartments of the production process. An approach about heavy metals was made. Some indicators were formulated and discussed: fertilization index (IA), return index (IR) and emission index (IE), which allowed an analysis of the sustainability and nutrients circulation. In the scenario analyzed for the model validation, it was concluded, one concludes that the amount of potassium, calcium and magnesium in circulation were sufficient for the fertilization of the culture, while the nitrogen, phosphorus and sulfur emitted were insufficient, requiring complementary fertilizations. It was concluded that the modern sugarcane agro-industry is conceptually very favorable to the sustainability, and still demands improvements for the effectiveness of these concepts. The verticalization of the production, even in monoculture, can contribute to the establishment of a handling balance favorable to the sustainability.
5

Ciclos biogeoquímicos como subsídio para a sustentabilidade do sistema agroindustrial da cana-de açúcar /

Barbosa, Valmir. January 2007 (has links)
Orientador: Miguel Angelo Mutton / Banca: Ailto Antonio Casagrande / Banca: Rafaella Rossetto / Resumo: O crescimento da cultura da cana-de-açúcar, frente à demanda global por energia renovável, provoca preocupações quanto à sua sustentabilidade. Nesse contexto, o objetivo deste trabalho é oferecer uma visão sistêmica do processo agroindustrial da cana-de-açúcar, do ponto de vista dos ciclos biogeoquímicos com a reciclagem de resíduos e efluentes. Para o desenvolvimento do trabalho foram elaborados modelos conceituais e numéricos, apresentando conceitos de ruptura e regeneração de ciclos, sustentabilidade cruzada, equação de configuração do canavial e coeficiente de uso cultural da terra. Foi elaborado um modelo das vias e de estratégias de uso de resíduos e efluentes para N, P, K, Ca, Mg e S, nos diversos compartimentos do processo de produção. Fez-se uma abordagem sobre metais pesados. Foram formulados e discutidos alguns indicadores: índice de adubação (IA), índice de retorno (IR) e índice de emissão (IE), que permitiram uma análise da circulação de nutrientes e da sustentabilidade. No cenário analisado para validação do modelo, concluiu-se que as quantidades de potássio, cálcio e magnésio em circulação foram suficientes para a adubação da cultura, enquanto o nitrogênio, fósforo e enxofre emitidos foram insuficientes, exigindo adubações complementares. Concluiu-se que a moderna agroindústria da cana-de-açúcar apresenta-se conceitualmente muito favorável à sustentabilidade, e ainda exige melhorias para a efetividade desses conceitos. A verticalização da produção, mesmo em monocultivo, pode contribuir para o estabelecimento de um equilíbrio de manejo favorável à sustentabilidade. / Abstract: The expansion of the sugarcane culture, up against global demand for renewable energy, provokes concerns as for its sustainability. In this context, the objective of this work was to offer a systemic view of the sugarcane agro-industrial process, from the point of view of the biogeochemical cycles with the effluent and residues recycling. For the development of the work conceptual and numerical models were elaborated, showing concepts of rupture and regeneration of cycles, crossed sustainability, cane field configuration equation and cultural land use coefficient. A model of the logistics and use strategies of effluent and residues for N, P, K, Ca, Mg and S was elaborated, in the several compartments of the production process. An approach about heavy metals was made. Some indicators were formulated and discussed: fertilization index (IA), return index (IR) and emission index (IE), which allowed an analysis of the sustainability and nutrients circulation. In the scenario analyzed for the model validation, it was concluded, one concludes that the amount of potassium, calcium and magnesium in circulation were sufficient for the fertilization of the culture, while the nitrogen, phosphorus and sulfur emitted were insufficient, requiring complementary fertilizations. It was concluded that the modern sugarcane agro-industry is conceptually very favorable to the sustainability, and still demands improvements for the effectiveness of these concepts. The verticalization of the production, even in monoculture, can contribute to the establishment of a handling balance favorable to the sustainability. / Mestre
6

Plant and arthropod diversity of maize agro–ecosystems in the Highveld and Lowveld regions of South Africa / Bheki George Maliba

Maliba, Bheki George January 2011 (has links)
Surveys of plant and selected insect species was conducted in Highveld and Lowveld agro–ecosystems of four provinces of South Africa, namely North–West, Mpumalanga, KwaZulu–Natal and Limpopo. The objectives of the study were to compare insect and plant diversity between localities (grassland and savanna) and treatments (maize field, semi–transformed and untransformed) to test for a general relationship between plant and insect diversity along a maize field–field margin gradient. Plant and insect diversity patterns were studied along the gradient and quantified in terms of richness and diversity indices. Plant and insect species compositional turnover was also measured along the maize field–field margin gradient. Plant diversity increased with increasing distance from maize fields into the margin. The flora in maize fields and of margins differed, but in contrast, insect species assemblages were similar in maize fields and margins. There was no statistical difference in insect diversity between treatments (maize field, semi–transformed and transformed). A relationship was revealed between plant and insect diversity, as plant diversity enhanced insect diversity. / Thesis (M.Sc. (Environmental Sciences))--North-West University, Potchefstroom Campus, 2011.
7

Plant and arthropod diversity of maize agro–ecosystems in the Highveld and Lowveld regions of South Africa / Bheki George Maliba

Maliba, Bheki George January 2011 (has links)
Surveys of plant and selected insect species was conducted in Highveld and Lowveld agro–ecosystems of four provinces of South Africa, namely North–West, Mpumalanga, KwaZulu–Natal and Limpopo. The objectives of the study were to compare insect and plant diversity between localities (grassland and savanna) and treatments (maize field, semi–transformed and untransformed) to test for a general relationship between plant and insect diversity along a maize field–field margin gradient. Plant and insect diversity patterns were studied along the gradient and quantified in terms of richness and diversity indices. Plant and insect species compositional turnover was also measured along the maize field–field margin gradient. Plant diversity increased with increasing distance from maize fields into the margin. The flora in maize fields and of margins differed, but in contrast, insect species assemblages were similar in maize fields and margins. There was no statistical difference in insect diversity between treatments (maize field, semi–transformed and transformed). A relationship was revealed between plant and insect diversity, as plant diversity enhanced insect diversity. / Thesis (M.Sc. (Environmental Sciences))--North-West University, Potchefstroom Campus, 2011.
8

Carabidae (Coleoptera): análise de fauna e flutuação populacional, em áreas de frutíferas e capoeira, Belém, Pará / Carabidae (Coleoptero): analysis of fauna and fluctuation population in areas fruit and capoeira, Belém, Pará

Oliveira, Helcio Hertz Gomes de [UNESP] 13 May 2016 (has links)
Submitted by HELCIO HERTZ GOMES DE OLIVEIRA null (helcio.hertz@ufra.edu.br) on 2016-08-01T20:12:29Z No. of bitstreams: 1 Tese Helcio Revisada_com numeracao.docx: 2631648 bytes, checksum: 5ca76cddaf85771277e9f55979e905de (MD5) / Rejected by Ana Paula Grisoto (grisotoana@reitoria.unesp.br), reason: Solicitamos que realize uma nova submissão seguindo as orientações abaixo: A versão final da dissertação/tese deve ser submetida no formato PDF (Portable Document Format). O arquivo PDF não deve estar protegido e a dissertação/tese deve estar em um único arquivo, inclusive os apêndices e anexos, se houver. Por favor, corrija o formato do arquivo e realize uma nova submissão. Agradecemos a compreensão. on 2016-08-02T20:08:22Z (GMT) / Submitted by HELCIO HERTZ GOMES DE OLIVEIRA null (helcio.hertz@ufra.edu.br) on 2016-08-03T12:59:04Z No. of bitstreams: 1 Tese Helcio Revisada_com numeracao.pdf: 2504407 bytes, checksum: e3ed8d614e79a5b02affdbfbc080304d (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-08-04T19:10:43Z (GMT) No. of bitstreams: 1 oliveira_hhg_dr_jabo.pdf: 2504407 bytes, checksum: e3ed8d614e79a5b02affdbfbc080304d (MD5) / Made available in DSpace on 2016-08-04T19:10:43Z (GMT). No. of bitstreams: 1 oliveira_hhg_dr_jabo.pdf: 2504407 bytes, checksum: e3ed8d614e79a5b02affdbfbc080304d (MD5) Previous issue date: 2016-05-13 / Este trabalho teve por objetivo caracterizar a diversidade e equitabilidade de espécies, similaridade de comunidades, flutuação populacional e influência de fatores metereológicos de Carabidae em fragmento florestal, capoeira do Black, e pomar de frutíferas: consórcio cupuaçu,Theobroma grandiflorum(Willd.ex Sreng.) K.Schum (Malvaceae)), taperebá (Spondias monbim L. (Anacardiacae)), muruci, (Byrsonima crassifolia ((L.) (Rich.) (Malpiguiaceae)), abricó, (Mammea americana Linn. (Clusiaceae)) e bacuri (Platonia insignis Mart. (Clusiaceae)). As amostragens foram realizadas mensalmente de janeiro a julho de 2014 e quinzenalmente de agosto de 2014 a julho de 2015, por meio de armadilhas tipo alçapão, instaladas na área experimental da Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA). Foram coletadas 207 espécimes de carabídeos pertencentes a 15 espécies.As espécies predominantes foram: Scarites sp. 1,Marsyas lampronotus Tschitscherine, 1901, Tetragonoderus laevigatus Chaudoir,Clivina sp. 1 e Aniara sepulchralis (Fabricius).M. lampronotus,ocorreu somente na capoeira em consórcio, cupuaçu e taperebá. Nacapoeira registrou-se a menor diversidade de espécies. A maior diversidade de espécies de carabídeos ocorreu em muruci e abricó, enquanto o maior número de indivíduos ocorreu em bacuri. Com o aumento da umidade relativa ocorreu redução da densidade populacional de A.sepulchralis. / This study aimed to characterize the diversity and equitability of species, similarity of species and fluctuation of Carabidae population and the influence of meteorological factors in forest fragment, capoeira do Black, and fruit orchard: Consortium of cupuaçu, Theobroma grandiflorum (Willd.ex Sreng.) K. Schum(Malvaceae)), taperebá (Spondias monbim L. (Anacardiacae)), muruci, (Byrsonima crassifolia ((L.) (Rich.) (Malpiguiaceae)), abricó, (Mammea americana Linn. (Clusiaceae)) e bacuri (Platonia insignis Mart. (Clusiaceae)). The samplings were carried monthly from January to July 2014 and fortnightlyof August 2014 to July 2015, through the pitfall trap, installed in the experimental area of the Brazilian Agricultural Research Corporation (EMBRAPA). There were collected 207 especimens of Carabidae, ordered in 15 species. The predominant species were: Scarites sp. 1, Marsyas lampronotus Tschitscherine, 1901, Tetragonoderus laevigatus Chaudoir, Clivina sp. 1 and Aniara sepulchralis (Fabricius). M.lampronotusoccurred in the capoeira and consortium cupuaçu e taperebá. In the capoeira was registered the lowest species diversity. The biggest species diversity of the Carabidae occurred in muruci and abricó, while the largest number of individuals occurred in bacuri. The increase in relative humidity influence on reducing the population density of the beetle A. sepulchralis.
9

Contribution à une théorie de la conception des agro-écosystèmes : Fonds écologique et inconnu commun / Contribution to a design theory of agro-ecosystems : Ecological fund and common unknown

Berthet, Elsa 23 September 2013 (has links)
L'agriculture fait face à une crise environnementale qui rend nécessaire la prise en compte du fonctionnement des « écosystèmes ». Mais ce concept de l'écologie donne peu de prise à l'action dans le secteur agricole. Les champs de littérature sur les « biens communs » et sur les « services écosystémiques », qui traitent de la gestion des écosystèmes, ont été abondamment développés et relayés par les politiques publiques. La thèse montre qu'ils cristallisent souvent les conflits entre les objectifs agricoles et les préoccupations écologiques sans pour autant permettre l'exploration de nouveaux systèmes agricoles.Notre thèse en sciences de gestion met en évidence qu'un nouvel enjeu pour la recherche scientifique est d'apprendre à piloter les régulations écologiques au sein des agro-écosystèmes de manière à rendre l'agriculture durable. Elle cherche à définir les modalités d'une démarche de conception des agro-écosystèmes : peuvent-ils faire l'objet de démarches de conception innovantes ? Quelles sont les méthodes pour les concevoir ? Et quels sont les modes de gouvernance appropriés ?L'analyse historique des raisonnements scientifiques en agronomie et en écologie met en évidence les raisons qui rendent difficiles aujourd'hui la conception des agro-écosystèmes, malgré les connaissances de plus en plus fines sur les régulations écologiques. La thèse modélise une classe d'objets particuliers, les « fonds écologiques », que les scientifiques introduisent pour aborder les agro-écosystèmes en s'affranchissant des seuls schémas connus. Elle montre l'intérêt de ne pas considérer les fonds écologiques comme des biens communs mais comme des « inconnus communs ». Le modèle proposé, testé sur un archétype de la production intensive en région céréalière, permet d'élaborer une méthode de conception collective et innovante des agro-écosystèmes. / Agriculture is facing an environmental crisis that makes it necessary to take into account the “ecosystem” functioning. But this concept of ecology is difficult to handle in the agricultural sector. Fields of literature on the "commons" and the "ecosystem services", which deal with the management of ecosystems, have been extensively developed and relayed by public policy. The thesis shows that they often freeze the conflict between agricultural objectives and environmental concerns without allowing the exploration of new farming systems.Our thesis in management science highlights the fact that a new challenge for scientific research is to learn to manage environmental regulations within agro-ecosystems in order to make agriculture sustainable. It aims to define a design approach of agro-ecosystems: can innovative design be applied to them? What are the methods to design agro-ecosystems? And what are the appropriate modes of governance?The historical analysis of scientific reasoning in agronomy and ecology highlights the reasons why the design of agro-ecosystems remains so difficult, despite finer knowledge on environmental regulations. The thesis models a particular class of objects, the “ecological fund” that scientists introduced to deal with agro-ecosystems while escaping the already known patterns. It shows the importance of considering the ecological funds not as common goods but as "common unknowns”. The proposed model, tested on an archetype of an intensive cereal production area, makes it possible to develop a method of collective and innovative design of agro-ecosystems.
10

Agro-ecological aspects when applying the remaining products from agricultural biogas processes as fertilizer in crop production

Domínguez, Gabriela Bermejo 15 August 2012 (has links)
Durch die Zunahme der Biogasproduktion in den letzten Jahren hat sich auch die Menge von Gärprodukten, die verbleibenden Rückstände, entsprechend erhöht. In Deutschland fallen jährlich mehr als 50 Millionen Tonnen Gärprodukte an, die als Dünger verwendet werden. Damit werden Nährstoffe in den Kreislauf landwirtschaftlicher Ökosysteme zurück-geführt. Allerdings sind die agroökologischen Wirkungen noch nicht hinreichend erforscht. Aus diesem Grund wurden die folgenden Parameter untersucht: Einfluss von trockenen und flüssigen Gärprodukten auf dem Ertrag von drei ausgewählten Fruchtarten im Vergleich zu oder in Kombination mit Mineraldünger in On-Farm Versuchen; Wachstum, Entwicklung und Ertrag von zwei ausgewählten Fruchtarten im Vergleich zu Mineraldünger, Gülle und Stallmist in einer vollständig randomisierten Blockanlage; Einfluss auf ausgewählte Bodenlebewesen im Vergleich zu Mineraldünger, Gülle und Stallmist in einer vollständig randomisierten Blockanlage. Zusätzlich wurde die Mineralisierung von flüssigen und festen Gärprodukten im Vergleich zu Gülle und Stallmist untersucht, um Effekte der verschiedenen Düngestoffe auf die Humusbildung unter kontrollierten Bedingungen zu bestimmen. / With the increase of biogas production in recent years, the amount of digestates or the remaining residues increased accordingly. Every year in Germany more than 50 million tons of digestates are produced, which are used as fertilizer. Thus nutrients return into the circulation of agricultural ecosystems. However, the agro-ecological effects have not been deeply researched until now. For this reason, the following parameters were quantified: the influence of dry and liquid fermentation products on the yield of three selected crops in comparison to or in combination with mineral-N-fertilizers in on-farm experiments; the growth, development and yield of two selected crops in comparison to mineral-N-fertilizer, liquid manure and farmyard manure in a randomized complete block design; selected soil organisms as compared to mineral-N-fertilizer, liquid manure and farmyard manure in a randomized complete block design. In addition, the mineralization of dry and wet digestates in comparison with liquid manure and farmyard manure was investigated in order to evaluate the effects of different fertilizers on the humus formation under controlled conditions.

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