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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.
11

Olše lepkavá (Alnus glutinosa L. Gaertn.) v symbióze s bakteriemi rodu Frankia a jejich růst na půdách výsypek po těžbě uhlí / European black alder (Alnus glutinosa L. Gaertn.) in symbiosis with Frankia and their growth on post-mining heap soils

Buchbauerová, Lucie January 2017 (has links)
Alder (Alnus glutinosa L. Gaertn.) is a species of a pioneer plant usually colonizing sites in the early stage of ecological succession, such as spoil heaps after open-cast brown coal mining in the Sokolov mining district in north western Bohemia, Czech Republic. These spoil heaps are very poor in nutrients available for plants, yet alders grow in a mutualistic relationship with actinomycetes Frankia, which live in root nodules of the alder plants. Frankia are able of fixing atmospheric nitrogen (N2) to ammonia (NH3) molecules, which can be then assimilate by alders, via enzyme nitrogenase. Thus, in the early stages of succession, alders have a competitive advantage to other non- fixing plant species living only on nitrates (NO3 - ) and ammonia ions (NH4 + ) present in soils. The aim of this study was to conduct and assess two greenhouse experiments. The first experiment studied the response of alder growth to presence of Frankia and arbuscular mycorrhizal fungi of order Glomerales. The performance of alder growth was significantly higher when alders were inoculated with both Frankia and mycorrhizal fungi in comparison to when alders have grown on their own or only with a mycorrhizal symbiont - both on 14 and 60 years old soils from Sokolov mines. In the second experiment, soil pH and iron (Fe) and...
12

Interactions between atmospheric nitrogen fixation and bioavailability of phosphorus in common bean (Phaseolus vulgaris L.) in some phosphorus-deficient soils of the Mediterranean basin / Interactions entre fixation d'azote atmosphérique et biodisponibilité du phosphore chez le haricot (Phaseolus vulgaris L.) dans quelques sols déficients en phosphore du bassin Méditerranéen

Aslan Attar, Hesham 14 September 2011 (has links)
La déficience des sols en éléments minéraux, particulièrement le phosphore (P) est une limitation majeure pour la croissance et le développement des légumineuses fixatrices d’azote. L’application des fertilisants phosphatés est une pratique traditionnelles pour satisfaire les besoins des plantes en P. Ainsi, pour tester l’efficacité d'utilisation du P pour la fixation symbiotique de l’azote (FSN) sous déficience en P, plusieurs lignées recombinantes (RILs) de haricot contrastantes dans leurs tolérance au déficit en P ont été utilisées. L’objectif principal de cette étude est d’évaluer l’aptitude de ces RILs pour l’amélioration de la fertilité phosphatée des sols déficients en P et sa relation avec la croissance et la nodulation de la légumineuse. Pour atteindre ces objectifs, des expériences ont été réalisées sous serre et en champs d'agriculteurs. Sous conditions contrôlées (serre) et non contrôlées (champs), les résultats ont montré une diminution du pH des sols associée à une augmentation du P assimilable. Une telle augmentation de la disponibilité du P a eu un effet positif sur la nodulation et la croissance de certaines des RILs testées. Aussi, l’amélioration de l’aptitude de ces RILs à fixer l’azote atmosphérique et l’élévation de la libération des protons H+ par les racines nodulées ont été quantifiés en milieu contrôlé. Ainsi la diminution du pH du sol a permis de réduire l’indisponibilité du P dans la solution du sol en le transformant en une forme directement biodisponible pour ces plantes. En outre, les résultats ont montré des différences significatives entre les différentes RILs en termes de la biomasse aérienne et nodulaire selon les sites d'observation. Nous concluons que, outre leur aptitude de fixation d’azote, l’utilisation efficace du phosphore pour sauver des engrais minéraux et de réduire les risques de pollution et pourrait améliorer la disponibilité des sols P. / The deficiency of soil minerals, particularly phosphorus (P) is a major limitation for growth and development of nitrogen-fixing by legumes. The application of phosphate fertilizers is a traditional practice to meet the needs of plant P. Thus, to test the effectiveness of use of P for symbiotic nitrogen fixation (NSF) under P deficiency, several recombinant inbred lines (RILs) of beans in their contrasting tolerance to P deficiency have been used. The main objective of this study is to assess the ability of these RILs to improve the fertility of soils deficient in phosphorus (P) and its relationship with growth and nodulation of the legume. To achieve these objectives, some experiments were conducted in greenhouses and fields. Under controlled conditions (greenhouse) and uncontrolled conditions (field), the results showed decreasing in soil pH associated with Proton release H+ and P acquisition. The increasing in available P had a positive effect on nodulation and growth of some RILs tested. Also, improving the ability of these RILs to fix atmospheric nitrogen and release H+ by nodulated roots were quantified in a controlled environment. Thus the decreasing in soil pH has reduced the un-availability of P in soil solution by transforming it into a bio-available form to the plants. In addition, the results showed significant differences between RILs in biomass and nodulation as observation in sites. We conclude that, in addition to their ability to fix nitrogen, effective use of phosphorus to save mineral fertilizer and reduce the pollution risks and could improve the availability of soil P.
13

Wirkung verschiedener Blattdünger-Formulierungen auf Wachstum und Ertragsbildung von Phaseolus vulgaris bei verminderter N-, Mg- und Mikronährstoffversorgung über die Wurzeln

Mpabansi, Antoine 21 January 1999 (has links)
Das Ziel der vorliegenden Arbeit bestand darin, in Modellversuchen in Wasserkultur und im Festsubstrat sowohl elementspezifische (Mg-, Fe-, Mn- oder Zn-Mangel) als auch komplexe N hrstoffmangelsituationen (gleichzeitiger Mangel an Fe, Mn und Zn) zu simulieren und die Wirkung pr ventiver resp. kurativer Blattapplikationen auf Wachstum und Ertrag von Buschbohnenpflanzen zu untersuchen. Zusammengefaát wurden folgende Ergebnisse erzielt. Bei unzureichendem Mg- und Fe-Angebot sowie bei gleichzeitigem Mangel an Fe, Mn und Zn wurden das Wachstum und die Ertragsbildung hochsignifikant vermindert. Die Auswirkungen des Mg-Mangels auf Wachstum und Ertrag wurden durch die pr ventive Blattapplikation erfolgreich ausgeglichen. Die verwendeten Mikron hrstoff-Formulierungen waren bei Fe-Mangel bzw. bei multipler Mikron hrstoff-Unterversorgung, im Gegensatz zu Mn- bzw. Zn-Mangel, weniger wirksam. Aufgrund des N hrstoffmangels w hrend der generativen Phase wurden die gebildeten Bl ten und H lsen abgeworfen. Den Mangelpflanzen erm glichte die Blattapplikation erst die H lsenbildung. Ausschlaggebend f r die H he des H lsenertrages war die Anzahl der gebildeten H lsen, da das H lsengewicht nicht wesentlich beeinfluát wurde. Aufgrund des verminderten N hrstoffangebotes im N hrmedium nahm die Konzentration der betroffenen N hrstoffe im Blatt bis in den kritischen Grenzwertbereich ab. Mit Ausnahme der Fe-Mangelvarianten wirkte die Blattd ngung dieser Abnahme der N hrstoffkonzentration erfolgreich entgegen. Hinsichtlich Wachstum Ertragsbildung und N hrstoffaufnahme wurden, sowohl bei den Mg- als auch bei den Mikron hrstoff-Blattd ngern keine von der Zusammensetzung abh ngigen Wirksamkeitsunterschiede festgestellt. Bez glich der untersuchten Parameter des Wachstums und der Ertragsbildung erwies sich die pr ventive Mg-Blattapplikation der kurativen gegen ber als hochsignifikant berlegen. Derart deutliche Wirksamkeitsunterschiede in Abh ngigkeit vom Applikationszeitpunkt blieben bei den Mikron hrstoff-Blattd ngern aus. Ein Mg- und Mikron hrstoffangebot von 10% im Jugendstadium konnte ein ungest rtes vegetatives Wachstum der Pflanzen gew hrleisten. Eine Mg- bzw. Mikron hrstoff-Unterversorgung der Pflanzen w hrend der generativen Phase bewirkte einen R ckgang des Samenertrages von ber 60% bis 80%. Mit Hilfe der Blattapplikationen w hrend der generativen Phase wurde der Abwurf der reproduktiven Organe hochsignifikant vermindert. Dadurch konnten ber 90% des Samenertrages der Kontrolle erreicht werden. Ungeachtet einer erfolgreichen Impfung mit Rhizobium blieben die Pflanzen ohne N-Startd ngung im Vergleich zu einer Startd ngung mit einer quivalentmenge von 40 kg N/ha bei Wachstum und Ertragsbildung hochsignifikant zur ck. Gemessen am Samenertrag konnten die Auswirkungen des N-Mangels im Jugendstadium durch eine Nachd ngung zu Bl hbeginn nicht mehr ausgeglichen werden. Durch die Kombination Nachd ngung zu Bl hbeginn und Blattapplikation w hrend der Kornf llungsphase wurde die Abscission von reproduktiven Organen signifikant vermindert und die h chste Ertragswirksamkeit erzielt. Unabh ngig von den Behandlungen lag der Rohproteingehalt der Samen bei 20%. Auch die anderen N hrstoffe der Samen lagen im normalen Konzentrationsbereich f r Buschbohne. / The aim of this study was to simulate as well specific (Mg-, Fe-, Mn- and Zn-deficiency) as complex nutrient deficiency situations in model systems using either nutrient solution or solid substrates and to investigate the effect of preventive or curative applications of foliar fertilizers on growth and yield of bean plants. Results may be summarized as follows: Insufficient supply of magnesium and iron or simultaneous deficiency in Fe, Mn and Zn resulted in highly significant reduction of growth and yield of bean plants. Effect of magnesium deficiency on growth and yield could be successfully compensated by preventive foliar fertilization. The applied micronutrient compounds were less successful in the case of iron deficiency or multiple micronutrient deficiency situations as compared to manganese or zinc deficiency. Nutrient deficiency during the generative phase resulted in dropping of flowers and pods. In deficient plants foliar fertilizer application was a precondition for pod formation. Since pod weight was not substantially affected by plant nutrition pod number was the decisive factor for pod yield. As a result of reduced nutrient supply in the substrates leaf concentration of investigated nutrients declined below critical deficiency levels. With exception of the Fe-deficiency variants application of foliar fertilizers successfully compensated for the decrease in leaf nutrient concentrations. The composition of Mg and micronutrient foliar fertilizers did not affect significantly plant growth, yield and nutrient uptake. For the investigated parameters of growth and yield formation preventive foliar application of magnesium fertilizers was significantly more effective as compared to curative application. Such distinctive differences in fertilizer effects with time of application could not be found in micronutrient fertilizers. Mg and micronutrient supply of as low as 10% of optimal supply during juvenile growth phase could guarantee undisturbed vegetative growth. Drastic decrease of magnesium or micronutrient supply during the reproductive phase resulted in a reduction of pod yield up to 60 - 80%. Foliar fertilizer application during the reproductive development significantly reduced dropping of reproductive organs and thus seed yields of more than 90% of control were achieved. Nevertheless after a successful inoculation with Rhizobium plants without a nitrogen start dressing had significantly lower growth and yields than those with a starter fertilization of 40 kg N/ha. With regard to seed yield the effects of nitrogen deficiency during the juvenile phase could not be compensated by late fertilization at the flowering stage. The combination of a late fertilization at the flowering stage and leaf application during pod filling resulted in decreased pod abscission and therefore in highest yields. Independently of treatments the raw protein content of the bean seeds approximated to 20%. Also other nutrients in the seeds were in the adequate range for Phaseolus bean.
14

Einfluss von Aussaatstärke, Bodenbearbeitung und Anbaumuster auf den Ertrag von Erbsen-Hafer-Gemengen / Effects of seed density, tillage system and experimental design on the yield of pea-oat intercrops

Neumann, Angelika 28 January 2010 (has links)
No description available.
15

Die Bedeutung der CO2-Fixierung von Leguminosenknöllchen für ihre Aktivität und Effizienz / The importance of nodule CO2 fixation for their activity and efficiency

Fischinger, Stephanie A. 28 May 2009 (has links)
No description available.
16

Consórcio de milho e Urochloa ruziziensis e inoculação com Azospirillum brasilense e seu efeito residual associado à adubação nitrogenada em feijoeiro de inverno / Mayze and Urochloa ruzizensis Intercropping system and inoculation with Azospirillum brasiliense and residual effect associate with the nitrogen management in winter bean

Sabundjian, Michelle Traete [UNESP] 29 February 2016 (has links)
Submitted by MICHELLE TRAETE SABUNDJIAN null (michelletraete@aluno.feis.unesp.br) on 2016-04-18T19:57:49Z No. of bitstreams: 1 Tese Michelle Traete Sabundjian.pdf: 7814537 bytes, checksum: 8ac173e36ebdd5ac1eddb3ff97807b70 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-04-20T11:46:07Z (GMT) No. of bitstreams: 1 sabundjian_mt_dr_ilha.pdf: 7814537 bytes, checksum: 8ac173e36ebdd5ac1eddb3ff97807b70 (MD5) / Made available in DSpace on 2016-04-20T11:46:07Z (GMT). No. of bitstreams: 1 sabundjian_mt_dr_ilha.pdf: 7814537 bytes, checksum: 8ac173e36ebdd5ac1eddb3ff97807b70 (MD5) Previous issue date: 2016-02-29 / Fundação Agrisus / O avanço de estudos das interações entre bactérias capazes de fixar o nitrogênio atmosférico em culturas agrícolas pode ajudar a definir estratégias para aumentar a eficiência do uso e diminuir a dependência do nitrogênio mineral. Assim, o objetivo do trabalho foi avaliar o efeito da inoculação de Azospirillum brasilense sobre o desenvolvimento e a produtividade do milho solteiro ou consorciado com Urochloa ruziziensis e o efeito residual deste consórcio, associados ao manejo de nitrogênio no feijoeiro de inverno. Para as gramíneas de verão, o delineamento experimental foi o de blocos ao acaso com 4 repetições e 8 tratamentos assim constituídos: (T1 - milho, T2 - milho + Azospirillum brasilense, T3 – Urochloa ruziziensis, T4 – Urochoa ruziziensis + Azospirillum brasilense, T5 - milho + Urochloa ruziziensis, T6 - milho - Azospirillum brasilense + Urochloa ruziziensis, T7 - milho + Urochloa ruziziensis - Azospirillum brasilense, T8 - milho – Azospirillum brasilense + Urochloa ruziziensis – Azospirillum brasilense). Para o feijão cultivado em sucessão, o delineamento experimental foi o de blocos ao acaso em esquema fatorial 8x4 com os tratamentos constituídos por 8 coberturas vegetais, citadas anteriormente, e combinação de 4 doses de nitrogênio em cobertura (0, 40, 80 e 120 kg ha-1 de N), com quatro repetições. Durante a condução do experimento, foram realizadas as seguintes avaliações: coberturas vegetais, características agronômicas, componentes de produção e produtividade das culturas do milho e feijão, além dos atributos físicos do solo. Pode-se concluir que, comparado aos demais tratamentos, a inoculação de Azospirillum brasilense proporcionou ao milho solteiro aumento da massa seca de plantas e massa de grãos por espiga, além de maior incremento de produtividade. O consórcio com Urochloa afetou a produtividade de grãos do milho, porém observou-se um aumento na produção e a qualidade da cobertura vegetal. A produtividade do feijoeiro foi influenciada pela cultura antecessora, apresentando melhores resultados quando o milho foi inoculado com Azospirillum brasilense. A aplicação de 60 kg ha-1 de N em cobertura apresentou os melhores resultados na produtividade do feijoeiro no primeiro ano, sendo que, no segundo ano, mesmo os tratamentos sem aplicação apresentaram resultados satisfatórios, o que pode ser atribuído à ciclagem de nutrientes oriundos das coberturas vegetais. Já os tratamentos em que a Urochloa ruziziensis estava presente demonstraram melhorias nos atributos do solo ao longo de 3 anos de cultivo. / The advanced studies on the interaction between atmospheric nitrogen-fixing bacteria and crops may contribute for the development of strategies to increase the mineral nitrogen-use-efficiency and decrease its dependency. The objective of the study was to evaluate the effect of inoculation with Azospirillum brasilense on development and yielding of single maize or maize intercropped with Urochloa ruziziensis as well as the residual effect of this intercropping system associated with the nitrogen management in winter bean. For summer grasses, the experimental design included a randomized block with four replications and eight treatments, as follows: (T1 - maize, T2 - maize + Azospirillum brasilense, T3 - Urochloa ruziziensis, T4 - Urochoa ruziziensis + Azospirillum brasilense, T5 - maize + Urochloa ruziziensis, T6 - maize - Azospirillum brasilense + Urochloa ruziziensis, T7 - maize + Urochloa ruziziensis - Azospirillum brasilense, T8 - maize - Azospirillum brasilense + Urochloa ruziziensis - Azospirillum brasilense). For the beans succession planting, the experimental design included randomized blocks in an 8x4 factorial scheme with treatments consisting of the eight cover crops mentioned previously and the combination of four nitrogen doses (0, 40, 80 and 120 kg ha-1 N), with four replications. During the experiment, the following assessments were performed: cover crops, agronomic characteristics, yield components and crop productivity of maize and beans in addition to the physical properties of the soil. The inoculation with Azospirillum brasilense provided the single maize with increased dry weight of plants and grain mass per spike; moreover, higher rates of productivity growth were observed when compared to the other treatments. The intercropping with Urochloa affected the maize grain productivity; however, there was an increase in yield and quality of cover crops. The bean yield was influenced by the previous crop, with better results when maize was inoculated with Azospirillum brasilense. The application of 60 kg ha-1 N in coverage provided better bean yield results in the first year. In the second year, the treatments without application demonstrated satisfactory results, which can be due to the nutrient cycling from the cover crops. Improvement of soil properties over the 3 years of cultivation was observed in the treatments including Urochloa ruziziensis. / Agrisus: 1140/13

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