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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

Efeito da fonte de nitrog?nio na libera??o de OH-/H+ na rizosfera e a intera??o com toxidez de alum?nio, estresse de salinidade e associa??o com Trichoderma sp. / Effect of nitrogen supply in release of OH-/ H+in the rhizosphere and interaction with aluminum toxicity, salinity stress and association with Trichoderma sp

Silva, Aldir Carlos 19 December 2013 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-05-12T11:45:17Z No. of bitstreams: 1 2013 - Aldir Carlos da Silva.pdf: 2147745 bytes, checksum: 9bf6569c9f3905b19282cebf10a5b003 (MD5) / Made available in DSpace on 2017-05-12T11:45:17Z (GMT). No. of bitstreams: 1 2013 - Aldir Carlos da Silva.pdf: 2147745 bytes, checksum: 9bf6569c9f3905b19282cebf10a5b003 (MD5) Previous issue date: 2013-12-19 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / The present study was conducted to evaluate if changes in rhizosphere pH of the growth media, controlled by the use of nitrogen sources could alleviate aluminum toxicity or effects caused by salinization. It is well documented that if a plant is absorbing and assimilating nitrate as a nitrogen source, it releases 0H - for growth substrate. If she is absorbing, assimilating, ammonia source releases H+. This occurs because the cells need to balance its electrochemical charge balance due to differential uptake of cations and anions. Despite being a general rule, scientific research directly use the nitrogen source in the growth medium, few have used other methods to add these sources, such as foliar application of nitrogen and its implications on load balancing. In this work, several alternative management of nitrogen application and its interactions with the toxicity caused by aluminum, excess salts and Trichoderma were studied. Sunflower (Helianthus annuus L.), Passionflower (Passiflora edulis f flavicarpa L.), Pineapple (Ananas comosus Merril), Coffee (Coffea arabica L), Almond (Terminalia catapa Linn) and Sombrero (Clitoria fairchildiana Howard). To conduct studies with plants Sunflower was initially performed a selection of more tolerant to acidity and salinity plants. The experiments were conducted on various substrates, soil and sand, simple and complete nutrient solution. The interaction between Trichoderma x nitrogen source for plants was conducted with Passion fruit and Sunflower. Were selected as moderately tolerant to aluminum to grow Sunflower Helium 360 , the other cultivars to toxicity occurred in contraction equal to or superior 160?M aluminum . Was selected as tolerant to salinity the H?lio 251 > 250 > 253, cultivars, with concentrations above 25 mM NaCl (1.90 dS.m?) plants were stop grown. After this step prior experiments cultivars tolerant or sensitive were used in accordance with the experimental needs. The experiments were divided into the following steps: In the first step, we evaluated the release of OH - / H + with application of nitrogen sources directly in the growth medium, and found that the nitrogen sources were unable to minimize the toxic effects of aluminum and salinity. In the second experiment, the effects of the release OH- /H+ with application of nitrogen sources in the association of the fungus Trichoderma sp. This fungus grown in petri dishes only at pH values above 5.0. The release of OH- / H+ did not influence the association of the fungus with the roots of plants of sunflower and Passion fruit. In the third step, we assessed whether foliar application of nitrogen sources could produce the same effects on efflux of loads in the rhizosphere. It was found that the nitrogen sources applied foliar increased the pH of the solution was applied when 10 % of nitrate and reduced the pH when applied 5 % and 10 % ammonium sulfate in plants of Coffee and 10 % of nitrate in Sunflower . The foliar application of nitrogen sources did not alter the toxicity of aluminum and not the salt effect on plants and Sunflower Coffee. / O presente trabalho foi realizado com o objetivo de estudar se varia??es do pH da rizosfera e do meio de crescimento, controladas pelo uso de fontes nitrogenadas, poderiam amenizar a toxidez de alum?nio ou os efeitos provocados pela saliniza??o. Na literatura cientifica ? bem documentado que se uma planta esta absorvendo e assimilando nitrato como uma fonte nitrogenada, ela libera 0H- para o substrato de crescimento. Se ela esta absorvendo e assimilando uma fonte amoniacal libera H+. Isto ocorre devido ?s c?lulas necessitarem equilibrar o seu balan?o eletroqu?mico de carga, devido ? assimila??o diferenciada de c?tions e anions. Apesar de ser uma regra geral, os trabalhos cient?ficos usam a fonte nitrogenada diretamente no meio de crescimento, poucos utilizaram outros m?todos de adicionar estas fontes, como por exemplo, a aplica??o foliar de nitrog?nio e suas implica??es no balan?o de carga. Neste trabalho foram estudadas diversas alternativas de aplica??o de nitrog?nio e as suas intera??es com a toxidez provocada por alum?nio, excesso de sais e com o fungo Trichoderma. Foram estudas diversas plantas: Girassol (Helianthus annuus L), Maracuj? (Passiflora edulis f. flavicarpa L.), Abacaxi (Ananas comosus Merril), Caf? (Coffea arabica L), Amendoeira (Terminalia catapa Linn) e Sombreiro (Clitoria fairchildiana Howard). Para realizar os estudos com plantas de Girassol foi realizada inicialmente uma sele??o de plantas mais tolerantes a acidez e a salinidade. Os experimentos foram realizados em diversos substratos, solo, areia, solu??o nutritiva simples e completa. A intera??o entre fungo Trichoderma x fonte nitrogenada foi realizado para plantas de Girassol e Maracuj?. Foram selecionadas como medianamente tolerantes ao alum?nio a cultivar de Girassol H?lio 360, as demais cultivares a toxidez ocorreu em contra??o igual ou superiora 160?M de alum?nio. Foi selecionada como tolerante a salinidade as cultivares H?lio 251>250>253, com concentra??es acima 25mM de NaCl (1,90 dS.m?) as plantas n?o cresceram.Ap?s esta etapa foram implantados experimentos com as cultivares previamente selecionas como sens?veis ou tolerantes e estas foram utilizadas de acordo com a necessidade experimental. Os experimentos foram divididos nas seguintes etapas: Na primeira etapa, avaliou-se a libera??o do OH-/H+ com aplica??o das fontes nitrogenadas diretamente no meio de crescimento, sendo verificado que as fontes nitrogenadas n?o conseguiram minimizar os efeitos t?xicos do alum?nio e da salinidade. Na segunda etapa, avaliou-se os efeitos libera??o do OH-/H+ com aplica??o das fontes nitrogenadas na associa??o do fungo Trichoderma. Este fungo cresceu em placas de petri somente em valores de pH acima de 5,0. A libera??o de OH-/H+ n?o influenciou a associa??o do fungo com as ra?zes de plantas de Girassol e Maracuj?. Na terceira etapa, foi avaliado se a aplica??o foliar das fontes nitrogenadas poderia produzir os mesmos os efeitos nos efluxos de cargas na rizosfera. Foi verificado que as fontes nitrogenadas aplicadas via foliar aumentaram o pH da solu??o quando foi aplicado 10% de nitrato e reduziram o pH quando foi aplicado 5% e 10% de sulfato de am?nia em plantas de Caf? e com 10% de nitrato em Girassol. A aplica??o foliar de fontes nitrogenadas n?o alteraram a toxidez de alum?nio e nem do efeito salino em plantas de Caf? e Girassol.
2

Comportamento produtivo e morfofisiol?gico do cons?rcio de milho e Crotalaria juncea em fun??o de intervalos entre semeaduras e sazonalidade de plantio / Productive and morphophysiological behavior of corn and Crotalaria juncea intercropping depending on intervals between sowing and planting seasonality

DALLA CHIEZA, Emerson 25 October 2013 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-11-29T17:41:33Z No. of bitstreams: 1 2013 - Emerson Dalla Chieza.pdf: 3379954 bytes, checksum: 59d75d0f24fddc7d958c8e981de2274a (MD5) / Made available in DSpace on 2018-11-29T17:41:33Z (GMT). No. of bitstreams: 1 2013 - Emerson Dalla Chieza.pdf: 3379954 bytes, checksum: 59d75d0f24fddc7d958c8e981de2274a (MD5) Previous issue date: 2013-10-25 / The objective of this study was to establish an organic management form of corn and Crotalaria juncea intercropping, which allows to optimize production "in situ" by fabaceae plant biomass with nitrogen input to the system, without the competition that presence of green manure can to exercise, follow to compromise the performance of cereal. Three experiments were conducted in the experimental field of Embrapa Agrobiology in Serop?dica - RJ, between of November 2010 to March 2012. The experimental design was randomized blocks with six treatments and four replications (Experiments 1 and 3) or three replicates (experiment 2). The first experiment took place between November 2010 and March 2011 and had the following treatments: T1 - C. juncea seeded seven days before corn crop and managed at 33 days after emergence (33 DAE), T2 ? C. juncea seeded at the same date of corn sowing (29 DAE), T3 - C. juncea seeded 14 days after corn sown (102 DAE), T4 - C. juncea seeded 28 days after corn sown (88 DAE), T5 and T6 - corn cropping alone. Experiment 2: T1 - C. juncea seeds seven days before the corn (43 DAE), T2 - C. juncea seeded at the same date of corn sowing (37 DAE), T3 - C. juncea seeded seven days after corn sown (74 DAE), T4 - C. juncea seeded 14 days after corn sown (67 DAE), T5 and T6 - corn cropping alone. To first and second experiments, T3, T4 and T6 had been received 70 kg ha-1 of nitrogen by castor bean pie. Treatments of the third experiment consisted: T1 and T2 - C. juncea seeded at the same date of corn sowing (30 DAE) at the single row, T3 and T4 ? corn cropping alone at the single row, T5 and T6 - C. juncea seeded at the same date of corn sowing (30 DAE) at the double rows. For T2 and T6 treatments the green manure was managed and removed from the area, and had been added castor bean pie (70 kg of N ha-1). Also T4 received castor bean pie as a N source for corn. Also in the first experiment, for T1 and T2 trataments proceeded up studies of decomposition and release of nutrients from waste C. juncea by litter bags with 8 intervals collections. For the third test is conducted studies agronomic performance of corn and nitrogen losses through ammonia volatilization to waste C. juncea, castor bean pie and cattle manure through static cameras semi open. When corn sown simultaneously, regardless of the time of sowing, C. juncea did not affect the yield of cereal, promoted the addition of nitrogen to the system able of promoting positive balances for this nutrient. When the green manure was sown 7 days before or 14 days after sowing corn in the summer period, exerted a negative influence on growth and yield of maize. The waste C. juncea showed high rates of decomposition and nutrient release, with half-life for N less than 14 days. Were found discrepant emission rates for ammonia and castor bean pie residue C. juncea, with accumulated losses of about 46 and 14 %, respectively. The arrangement in double rows corn planting did not influence the yield of cereal. The results post the consortium in corn and C. juncea sown simultaneously as a promising culture system, capable of producing corn grain above the average yield of Rio of Janeiro state. / O objetivo geral deste trabalho foi estabelecer uma forma de manejo org?nico do cons?rcio entre as culturas de milho e Crotalaria juncea, que possibilite otimizar a produ??o ?In situ? de biomassa vegetal pela fabaceae, com aporte de nitrog?nio ao sistema, sem que a presen?a do adubo verde exer?a competi??o capaz de comprometer o rendimento do cereal. Foram conduzidos tr?s experimentos no campo experimental da Embrapa Agrobiologia em Serop?dica ? RJ, entre os meses de novembro de 2010 e mar?o de 2012. O delineamento experimental utilizado foi o de blocos ao acaso, com seis tratamentos e quatro repeti??es (experimentos 1 e 3) ou tr?s repeti??es (experimento 2). O primeiro experimento ocorreu entre novembro de 2010 e mar?o de 2011 e teve os seguintes tratamentos: T1?C. juncea semeada sete dias antes da cultura do milho e manejada aos 33 dias ap?s emerg?ncia (33 DAE); T2?C. juncea semeada simult?nea ao milho (manejo aos 29 DAE); T3?C. juncea semeada 14 dias ap?s o milho (manejo aos 102 DAE) + 70 kg N ha-1; T4?C. juncea semeada 28 dias ap?s o milho (manejo aos 88 DAE) + 70 kg N ha-1; T5-milho em monocultivo e T6-milho em monocultivo + 70 kg N ha-1. Experimento 2 (abril a setembro de 2011): T1?C. juncea semeada sete dias antes da cultura do milho (manejo aos 43 DAE); T2?C. juncea semeada simult?nea ao milho (manejo aos 37 DAE); T3?C. juncea semeada sete dias ap?s o milho (manejo aos 74 DAE) + 70 kg N ha-1; T4?C. juncea semeada 14 dias ap?s o milho (manejo aos 67 DAE) + 70 kg N ha-1; T5- milho em monocultivo e T6?milho em monocultivo+ 70 kg N ha-1. Os tratamentos do 3? Experimento (novembro de 2011 a mar?o de 2012) consistiram em: T1-C. juncea semeada simult?nea ao milho em fila simples com manejo aos 30 DAE e a biomassa da C. juncea mantida na ?rea; T2?C. juncea semeada simult?nea ao milho em fila simples com manejo aos 30 DAE com remo??o da parte a?rea de C. juncea e aplica??o de 70 kg N ha-1 via torta de mamona; T3- milho monocultivo em fila simples; T4 ?milho monocultivo em fila simples + 70 kg N ha-1; T5- C. juncea semeada simult?nea ao milho em fila dupla com manejo aos 30 DAE e a biomassa da C. juncea mantida na ?rea; T6 ? C. juncea semeada simult?nea ao milho em fila dupla com remo??o da parte a?rea de C. juncea e aplica??o de 70 kg N ha-1. Para todos os experimentos, o nitrog?nio aplicado em cobertura teve como fonte a torta de mamona. Nos dois primeiros ensaios foram realizados estudos morfofisiol?gicos dos cultivos a partir da an?lise funcional do crescimento de plantas, al?m do balan?o monet?rio e balan?o aparente de nitrog?nio. Tamb?m no experimento I, para T1 e T2, procederam-se estudos de decomposi??o e libera??o de nutrientes dos res?duos de C. juncea via sacolas de decomposi??o, com 8 intervalos de coletas. Para o terceiro ensaio procederam-se estudos de desempenho agron?mico do milho, an?lise econ?mica e balan?o de nitrog?nio. Tamb?m foram feitos estudos das perdas de nitrog?nio via volatiliza??o de am?nia para res?duos de C. juncea, torta de mamona e esterco bovino, atrav?s de c?meras est?ticas semi abertas em oito intervalos de coleta. Quando semeada simultaneamente ao milho, independente da ?poca de semeadura, a C. juncea n?o comprometeu o rendimento do cereal, promoveu a adi??o de nitrog?nio ao sistema capaz de promover balan?os positivos para este nutriente. Quando o adubo verde foi semeado 7 dias antes ou 14 dias ap?s a semeadura do milho, no per?odo de ver?o, esse exerceu influ?ncia negativa no crescimento e na produ??o de gr?os do milho. Os res?duos de C. juncea apresentaram elevadas taxas de decomposi??o e libera??o de nutrientes, com tempo de meia vida para N de menos de 14 dias. Foram encontradas discrepantes taxas de emiss?o de am?nia para torta de mamona e res?duos de C. juncea, com perdas acumuladas de cerca de 46 e 14%, respectivamente. O arranjo em fileiras duplas de plantio de milho n?o influenciou no rendimento do cereal. Os resultados encontrados postam o cons?rcio em milho e C. juncea semeados simultaneamente como um promissor sistema de cultivo, capaz de proporcionar produ??o de gr?os de milho acima da m?dia produtiva do estado do Rio de Janeiro.

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