• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 47
  • Tagged with
  • 47
  • 47
  • 39
  • 35
  • 19
  • 18
  • 17
  • 17
  • 16
  • 16
  • 16
  • 15
  • 15
  • 13
  • 13
  • 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

An?lise do efeito do spray de nitrog?nio l?quido em culturas de bact?rias enterococcus faecalis : estudos in vitro

Batista, Paulo S?rgio 31 March 2006 (has links)
Made available in DSpace on 2015-04-14T13:29:47Z (GMT). No. of bitstreams: 1 347076.pdf: 3330942 bytes, checksum: 3ea4026a1c59584ef47b662a3c10d4fb (MD5) Previous issue date: 2006-03-31 / A crioterapia com nitrog?nio l?quido tem sido utilizada em diversas ?reas, inclusive com finalidades terap?uticas. Na Microbiologia, ? vasto o n?mero de pesquisas que abordam o efeito controlador do frio em bact?rias (criobiologia), principalmente com a inten??o de evitar sua prolifera??o. No entanto, pouco se sabe a respeito do efeito da queda brusca e intensa da temperatura, como aquela provocada pelo nitrog?nio l?quido, na forma de spray, em microrganismos como as bact?rias Enterococcus faecalis, freq?entemente encontradas em canais com polpas necrosadas, infec??es pulpares e periapicais refrat?rias ao tratamento endod?ntico. Dessa forma, o objetivo deste trabalho foi analisar, in vitro, o efeito do spray de nitrog?nio l?quido nessas bact?rias cultivadas em laborat?rio, em meios de cultura l?quido (caldo BHI) e s?lido (?gar-BHI). Para isso, uma suspens?o de soro fisiol?gico concentrada ...
2

Caracteriza??o fisiol?gica da resposta a aduba??o nitrogenada em duas cultivares de arroz

ZONTA, Everaldo 11 July 1996 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-09-19T17:42:20Z No. of bitstreams: 1 1996 - Everaldo Zonta.pdf: 1943123 bytes, checksum: 68d390944248ef0f006da2af6d6385fc (MD5) / Made available in DSpace on 2017-09-19T17:42:20Z (GMT). No. of bitstreams: 1 1996 - Everaldo Zonta.pdf: 1943123 bytes, checksum: 68d390944248ef0f006da2af6d6385fc (MD5) Previous issue date: 1996-07-11 / CNPq / An experiment was carried out to study the seasonal pattern of dry mass and nitrogen (N) distribution in the vegetative and reproductive parts of two rice cultivars of contrasting aerial architecture, as a function of the application of N in the maximum tillering stage. Substrate from the Ap horizon of a Red Yellow Podzolic soil was used as substrate. The cultivars Comum Branco (dryland) and IAC 4440 (irrigated) were combined with five application levels of N (as Ammonium Sulfate): 0, 2, 4, 6 and 8 g N m-2 in the maximum tillering, and grown in pots arranged in a completely randomized, greenhouse. During the plant cycle, seven successive collections were carried out in order to follow the phasic development as days after planting (DAP): beginning of tillering, maximum tillering, panicle differentiation, stem elongation, flowering, milky / pasty grain and physiological maturation of the grain, which corresponded to collections at 20, 40, 60, 80, 100, 115 and 135 DAP respectively. In each collection were determined the dry mass of: green and senescent leaves, stems and sheaths and roots. The green leaf area and root area were also determined. The N contents were determined in all these fractions by micro Kjeldhal technique. In the final collection the components of the production were evaluated: mass and number of panicle, viable and sterile grain, and their corresponding N contents. The experimental data were combined for the purpose of analysis of variance, in the form of a cultivar factorial x dose x DAP . Primary functions were adjusted from the data of dry mass and total N, foliar and root area, from which the growth and accumulation rates were derived, to obtain net assimilation rates and N influx rates. it was observed that during the period prior to flowering there were no differences in accumulation of total dry matter between the cultivars. There was a higher dry mass allocated in stalks and sheaths, and lower weight of senescent leaves mass in IAC 4440. The partition of dry mass in favor of roots was similar in both cultivars. The cultivar IAC 4440 established a potential productive superiority due to its greater number of tillers. As a consequence, it maintained a longer duration of photosynthetically active leaf area, resulting in a higher daily accumulation rate of dry matter and leaf area. Regarding the N accumulation patterns in the different biomass fractions, the same trend as that observed for dry mass accumulation was observed. However, the maximum rate of maximum accumulation of N occurred in both cultivars, rather than the maximum dry matter accumulation. Leaf N contents in both cultivars were similar until flowering. IAC 4440 had greater specific leaf area in the period, suggesting greater leaf N dilution. When compared to leaf area equality, the net assimilation rate was higher in IAC 4440, which indicates that the overproduction of area, affected the photosynthetic potential in this cultivar, to a greater degree than in Common White. In the post-flowering period, the dry matter partitioning pattern, which was rigidly fixed in pre-flowering, was manifested in a sustained remobilization of photoassimilates and N to the panicle in IAC 4440, evidenced by the reduction of dry mass and N contents of stalks and sheaths during the first 15 days post-flowering and additional contribution of N and C from marked leaf senescence in the maturation period. There was detention of the photo-assimilates and N remobilization of the panicle in Common White, after 15 days post-flowering, with consequent accumulation of dry matter and N in leaf stems and sheaths. The development of a secondary drainage originated in post-flowering neo-tillering may have subtracted photosynthates, otherwise able to be applied in the filling of the growing panicle. A higher grain weight per plant in IAC 4440 was explained by a higher number of panicles and a higher number of viable seeds, and lower crude protein levels, compared to White Common. Regarding the dry mass and nitrogen distribution patterns during the cycle of the cultivars, the effects resulting from the single application of N at the maximum tillering were diluted during the development of the plants, so that they had very little effect on the dynamics of retranslocation of C and N after flowering. This dilution effect was responsible for the non-significance of the interaction of practically none of the primary descriptive growth parameters of the cultivars. No effect of N on phasic development was also noted. The higher levels of N applied favored an increase in net assimilation due to an increase in leaf N content. At higher levels of N application, leaf mass increased without area promotion, which was evidenced by the increase in its specific weight. However, the N content did not significantly reduce leaf senescence; The application of N did not affect significantly the production, only affecting an increase in the percentage of sterility of the spikelets, which counterbalanced the gain of one panicle per plant. As a global result of the work, it was concluded that the patterns of dry matter production and C and N remobilization to the grain, are regulated genetically, showing cultivar specificity. Therefore, nitrogen fertilization is efficient only in order to ensure high rates of physiological activity of panicles and other organs related to grain filling, but not in changing the pattern itself. / Foi instalado um experimento com o objetivo de estudar o padr?o sazonal de distribui??o de massa seca e nitrog?nio (N) nas partes vegetativas e reprodutivas de duas cultivares de arroz de arquitetura a?rea contrastante, em fun??o da aplica??o de N no est?gio de m?ximo perfilhamento. Usou-se como substrato terra proveniente do horizonte Ap de um solo Podz?lico Vermelho Amarelo. As cultivares Comum Branco (de sequeiro) e IAC 4440 (irrigada) foram combinadas com cinco n?veis de aplica??o de N (na forma de Sulfato de Am?nia): 0, 2, 4, 6 e 8 g N m-2, no est?gio de m?ximo perfilhamento, e cultivadas em potes dispostos de forma inteiramente casualizada, em casa de vegeta??o. Durante o ciclo das plantas foram realizadas sete coletas sucessivas, de forma a acompanhar o desenvolvimento f?sico como dias ap?s plantio (DAP): in?cio do perfilhamento, perfilhamento m?ximo, diferencia??o da pan?cula, elonga??o de colmos, flora??o, gr?o leitoso/pastoso e matura??o fisiol?gica do gr?o, o que correspondeu ? coletas aos 20, 40, 60, 80, 100, 115 e 135 DAP respectivamente. Em cada coletas foram determinados a massa seca de: folhas verdes e senescentes, colmos e bainhas e ra?zes. A ?rea foliar verde e ?rea radicular foram tamb?m determinadas. Os teores de N foram determinados em todas estas fra??es, por t?cnica de micro Kjeldhal. Na coleta final foram avaliados os componentes da produ??o: massa e n?mero de pan?cula, gr?o vi?vel e est?ril, e seus correspondentes teores de N. Os dados experimentais foram combinados para finalidade de an?lise de vari?ncia, na forma de um fatorial cultivar x dose x DAP. Fun??es prim?rias foram ajustadas a partir dos dados de massa seca e conte?do total de N, ?rea foliar e radicular, das quais foram derivadas as taxas de crescimento e de ac?mulo, para f?ns de obten??o das taxas de assimila??o l?quida e influxos de N. Concluiu-se que durante o per?odo anterior ? flora??o, n?o existiram diferen?as em ac?mulo de mat?ria seca total entre as cultivares. Houve maior massa seca alocada em colmos e bainhas, e menor peso de massa de folhas senescentes em IAC 4440. A parti??o de massa seca em favor de ra?zes resultou similar em ambas as cultivares. A cultivar IAC 4440 estabeleceu uma superioridade produtiva potencial em fun??o de seu maior n?mero de perfilhos. Como consequ?ncia, manteve maior dura??o de ?rea foliar fotossinteticamente ativa, resultando em maior taxa de ac?mulo di?rio de mat?ria seca e ?rea foliar. Com rela??o aos padr?es de ac?mulo de N nas diferentes fra??es da biomassa, foi observado a mesma tend?ncia que a verificada para ac?mulo de massa seca. Por?m, a taxa m?xima de m?ximo ac?mulo de N, aconteceu em ambas as cultivar, antes do que os m?ximos de ac?mulo de mat?ria seca. Os teores de N foliares em ambas as cultivares foram similares at? a flora??o. IAC 4440 teve maior ?rea foliar espec?fica no per?odo, sugerindo maior dilui??o de N foliar. Quando comparadas ? igualdade de ?rea foliar, a taxa de assimila??o l?quida foi superior em IAC 4440, o que indica que a sobreprodu??o de ?rea, prejudicou o potencial fotossint?tico nesta cultivar, em maior grau que em Comum Branco. No per?odo p?s-flora??o, o padr?o de parti??o de mat?ria seca ao gr?o, o qual foi rigidamente fixado na pr?-flora??o, manifestou-se em uma remobiliza??o sustentada de fotoassimilados e N ? pan?cula em IAC 4440, evidenciado pela redu??o de massa seca e conte?do de N de colmos e bainhas durante os primeiros 15 dias p?s-flora??o e contribui??o adicional de N e C a partir de acentuada senesc?ncia foliar no per?odo de matura??o. Houve deten??o da remobiliza??o de fotoassimilados e de N ? pan?cula em Comum Branco, ap?s os 15 dias p?s-flora??o, com consequente ac?mulo de mat?ria seca e N em colmos e bainhas foliares. O desenvolvimento de um dreno secund?rio originado em neo-perfilhamento p?s-flora??o, pode ter subtra?do fotossintatos, de outra forma, pass?veis de serem aplicados no enchimento da pan?cula em crescimento. Um maior peso de gr?os por planta em IAC 4440 foi explicado por maior n?mero de pan?culas e maior n?mero de sementes vi?veis, e menores teores de prote?na bruta, em rela??o a Comum Branco. Com rela??o aos padr?es de distribui??o de massa seca e nitrog?nio durante o ciclo das cultivares, os efeitos decorrentes da aplica??o ?nica de N por ocasi?o do m?ximo perfilhamento foram dilu?dos durante o de desenvolvimento das plantas, de forma que tiveram efeito muito reduzido sobre a din?mica de retransloca??o de C e N p?s-flora??o. Esse efeito de dilui??o foi respons?vel pela n?o significa??o da intera??o de praticamente nenhum dos par?metros prim?rios descritivos de crescimento das cultivares. Tamb?m n?o foi notado efeito do N no desenvolvimento f?sico. Os maiores n?veis de N aplicados, favoreceram um aumento da assimila??o l?quida devido ? um aumento no teor de N foliar. Aos maiores n?veis de aplica??o de N, o peso de massa foliar aumentou, sem promo??o de ?rea, o que foi evidenciado pelo aumento do seu peso espec?fico. Entretanto, o teor de N n?o reduziu significativamente a senesc?ncia foliar; A aplica??o de N n?o afetou significativamente a produ??o, incidindo apenas num aumento da percentagem de esterilidade das espiguetas, que contrabalanceou o ganho de uma pan?cula por planta. Como resultado global do trabalho, foi concluido que os padr?es de produ??o de mat?ria seca e de remobiliza??o de C e N ao gr?o, est?o regulados geneticamente, mostrando especificidade de cultivar. Portanto, a fertiliza??o nitrogenada ? eficiente apenas no sentido de assegurar altas taxas de atividade fisiol?gica das pan?culas e demais ?rg?os relacionados ao enchimento de gr?os, mas n?o na mudan?a do padr?o em s?.
3

Uso de probi?tico sobre a energia e digestibilidade de nutrientes em ra??es para su?nos / Use of probiotic on energy and nutrient digestibility in diets for pigs

Souza, Gabrielle Silva 19 September 2014 (has links)
Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2016-01-12T13:44:42Z No. of bitstreams: 2 license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) gabrielle_silva_souza.pdf: 711781 bytes, checksum: 08d13594e2bccca237e6f3c4656e613c (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2016-01-12T13:45:15Z (GMT) No. of bitstreams: 2 license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) gabrielle_silva_souza.pdf: 711781 bytes, checksum: 08d13594e2bccca237e6f3c4656e613c (MD5) / Made available in DSpace on 2016-01-12T13:45:16Z (GMT). No. of bitstreams: 2 license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) gabrielle_silva_souza.pdf: 711781 bytes, checksum: 08d13594e2bccca237e6f3c4656e613c (MD5) Previous issue date: 2014 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Chr. Hansen / Para avaliar os efeitos do uso de probi?ticos sobre a metabolizabilidade da energia e digestibilidade de nutrientes em ra??es para su?nos, realizou-se um experimento com 32 su?nos, machos castrados, com peso de 31,2?4,7Kg, distribu?dos em delineamento experimental em blocos casualizados, em arranjo fatorial 2x2, sendo dois n?veis de energia metaboliz?vel (3200 e 3300 kcal/kg de energia metaboliz?vel), com ou sem adi??o de probi?tico, em 4 tratamentos e 8 repeti??es com um animal por unidade experimental. Os tratamentos foram assim constitu?dos: T1 - ra??o com 3200 kcal/kg de EM (3200 EM), T2 -ra??o T1 + 400 g/tonelada de probi?tico (3200 EM+P), T3 - ra??o com 3300 kcal/kg de EM (3300 EM) e T4 - ra??o T3 + 400 g/tonelada de probi?tico (3300 EM+P) e o per?odo experimental foram de 10 dias, sendo 5 dias para adapta??o dos su?nos ?s gaiolas e 5 dias para coleta de fezes e urina. Foram determinados os valores digest?veis da energia (ED), energia metaboliz?vel (EM), energia metaboliz?vel corrigida para balan?o de nitrog?nio (EMn), prote?na bruta (PB), extrato et?reo (EED), fibra bruta (FD), fibra em detergente neutro (FDND) e fibra em detergente ?cido (FDAD), mat?ria mineral (MMD), c?lcio (CaD) e f?sforo (PPD) das ra??es, para c?lculo dos coeficientes de metabolizabilidade e digestibilidade da energia e dos nutrientes. Maiores valores (P<0,05) de ED, EM e EMn, FDAD, EED e coeficiente de digestibilidade de extrato et?reo foram determinados na ra??o contendo 3300 EM+P. N?o houve diferen?a (P>0,05) entre as ra??es em rela??o aos coeficientes de digestibilidade e metabolizabilidade de energia, assim como para os valores de MMD, CaD, PPD, PD, FD e FDND. A inclus?o de probi?tico nas ra??es proporcionou incremento na energia das ra??es, devido ? melhoria na digestibilidade da FDA e EE. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Zootecnia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2014. / ABSTRACT To evaluate the effects of probiotics on the metabolizable energy and digestibility of nutrients in diets for pigs, we made an experiment with 32 pigs, barrows weighing 31.2 ? 4,7Kg distributed in experimental design randomized blocks in a 2x2 factorial arrangement, with two levels of metabolizable energy (3200 and 3300 kcal / kg metabolizable energy), with or without added probiotic in 4 treatments and 8 repetitions with an animal per experimental unit. Treatments were: T1 - diet with 3200 kcal / kg of ME (3200 ME), T2 - T1 diet + 400 g / ton probiotic (3200 ME + P), T3 - diet with 3300 kcal / kg of ME (3300 ME) and T4 - T3 diet + 400 g / ton probiotic (3300 ME + P) and the experimental period was 10 days, with 5 days for adaptation of pigs cages and 5 days for collection of faeces and urine. We evaluated the digestible of energy (DE), metabolizable energy (ME), metabolizable energy corrected for nitrogen (MEn), crude protein (CP), ether extract (EE), crude fiber (FD), neutral detergent fiber (DNDF) and acid detergent fiber (DADF), mineral matter (MMD), calcium (CaD) and phosphorus (PPD) to calculate the coefficients of digestibility and metabolizable energy and nutrients. Higher values were found ??(P <0.05) of ED, ME, MEn, DADF, EE and digestibility of ether extract in diets containing 3300 ME + P. There was no difference (P> 0.05) among diets in relation to digestibility and metabolizable energy, as well as the values ??of PD, FD, DNDF, MMD, CaD and PPD. The inclusion of probiotics in feed resulted in increased energy rations due to improved digestibility of DADF and EE.
4

Metabolismo de nitrog?nio em plantas de arroz (Oryza sativa L.) em associa??o com bact?rias diazotr?ficas endof?ticas / Nitrogen metabolism in rice plants (Oryza sativa, L.) inoculated with endophytic diazotrophic bacteria

Sabino, Daniele Cristina Costa 26 March 2003 (has links)
Made available in DSpace on 2016-04-28T14:58:31Z (GMT). No. of bitstreams: 1 2003- Daniele Cristina Costa Sabino.pdf: 534915 bytes, checksum: c4045f2c9f540e49bb6c91877c6845ff (MD5) Previous issue date: 2003-03-26 / Funda??o Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Rice is colonized by diazotrophic bacteria that can act as root growth promoting, as well as to increase plant nutrition throw the biological nitrogen fixation process. These associations can modify the plant physiology since they compete for carbohydrate and other compounds necessary to host plants. The aim of this work was to evaluate the influence of the endophytic diazotrophic bacteria, Burkholderia brasilensis and Herbaspirillum seropedicae on nitrogen metabolism of two rice cultivars (IR42 and IAC4440). The experiment was carried out in pots containing 3 kg of soil, fertilized with 3 nitrogen levels (0, 40, and 80 kg N ) as (NH4)2SO4, and three inoculation treatments (H. seropedicae (ZAE94), B. brasilensis (M130) and the mixture of both). The plants were harvested at vegetative (45 days of inoculation) and flowering stages (according to the cycle of each cultivar). Bacterial counting, dry matter, N content and the concentration of nitrogen compounds were measured at each harvest. The results showed no statistical differences on bacterial counting. The number of root bacteria was higher than in shoots. A population reduction occurred on the flowering stage as compared to vegetative one. Cultivar IR42 responded to inoculation more noticiable than IAC4440. The dry matter accumulation of the IR42 cultivar at the vegetative stage varied with inoculation and nitrogen dose applied. This cultivar accumulated higher amounts of nitrogen when inoculated with ZAE94 strain, independent of the nitrogen applied. Concentrations of nitrate, free amino acid and soluble sugar in the aerial parts were higher in plants fertilized with 40kgN/ha and inoculated with the mixture of bacteria. These results suggested that the diazotrophic bacteria inoculation could modify the plants nitrogen metabolism and theses effects were variable according to the rice cultivars and nitrogen fertilization level applied. / O arroz (Oryza sativa L.) ? colonizado por bact?rias diazotr?ficas que, podem atuar como promotoras de crescimento das ra?zes, assim como melhorar a nutri??o da planta atrav?s do N2 fixado biologicamente. No entanto, estas associa??es podem modificar a fisiologia das plantas, uma vez que as bact?rias diazotr?ficas para fixarem o nitrog?nio necessitam de carboidratos e outros componentes, competindo, deste modo, com as plantas hospedeiras. Assim sendo, este trabalho teve como objetivo avaliar a influ?ncia da inocula??o de bact?rias diazotr?ficas endof?ticas Burkholderia brasilensis e Herbaspirillum seropedicae no metabolismo de nitrog?nio de duas cultivares de arroz adubadas ou n?o com nitrog?nio mineral. Um experimento em condi??es de vasos foi realizado na ?rea experimental da Embrapa Agrobiologia com as cultivares de arroz IR42 e IAC4440. A inocula??o consistiu no uso das estirpes ZAE94 de Herbaspirillum seropedicae, e M130 de Burkholderia brasilensis , a mistura destas duas estirpes e da testemumha (controle n?o inoculado). A aduba??o na forma de (NH4)2SO4, foi aplicada nas concentra??es de 0, 40 e 80 kgN/ha. As coletas foram realizadas no per?odo vegetativo (45 dias) e no florescimento (de acordo com o ciclo de cada cultivar). Os par?metros avaliados foram a presen?a das bact?rias nos tecidos das plantas, o ac?mulo de mat?ria seca da parte a?rea, o ac?mulo de N, e a concentra??o dos compostos nitrogenados na planta. Os resultados mostraram que n?o houve diferen?as nas popula??es das bact?rias em fun??o da inocula??o, por?m, o n?mero de bact?rias na raiz foi ligeiramente maior do que na parte a?rea. Foi tamb?m observado uma redu??o na popula??o no per?odo de florescimento, em rela??o ao per?odo vegetativo. De um modo geral, a cultivar IR42 apresentou maiores respostas ? inocula??o, quando comparada com a cultivar IAC4440. O ac?mulo de mat?ria seca da cultivar IR42 no per?odo vegetativo, variou com a inocula??o e a dose de nitrog?nio aplicada. Por?m, a percentagem de nitrog?nio (%N) acumulada na parte a?rea destas plantas, foi maior nos tratamentos inoculados com a estirpe ZAE94, independente da dose de nitrog?nio aplicada. As plantas que receberam 40 kgN/ha e foram inoculadas com a mistura, apresentaram as maiores concentra??es de nitrato, amino?cidos livres e a??cares sol?veis na parte a?rea. Os resultados obtidos sugerem que a inocula??o das bact?rias diazotr?ficas modifica o metabolismo de nitrog?nio e que este efeito foi diferenciado em fun??o da variedade e da dose de nitrog?nio aplicada.
5

Silagens com diferentes propor??es de capim-marandu e amendoim forrageiro / Silages containing different proportions of Marandu Grass and peanut

Gomes, Fran?oise Mara 18 July 2013 (has links)
Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-01-05T11:59:39Z No. of bitstreams: 2 francoise_mara_gomes.pdf: 474916 bytes, checksum: 3c5a4eac9fcd5ab28c70fd667d29e48f (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-01-05T12:09:22Z (GMT) No. of bitstreams: 2 francoise_mara_gomes.pdf: 474916 bytes, checksum: 3c5a4eac9fcd5ab28c70fd667d29e48f (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-01-05T12:09:44Z (GMT) No. of bitstreams: 2 francoise_mara_gomes.pdf: 474916 bytes, checksum: 3c5a4eac9fcd5ab28c70fd667d29e48f (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Made available in DSpace on 2015-01-05T12:09:45Z (GMT). No. of bitstreams: 2 francoise_mara_gomes.pdf: 474916 bytes, checksum: 3c5a4eac9fcd5ab28c70fd667d29e48f (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Previous issue date: 2013 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / O estudo foi conduzido na Universidade Federal de Vi?osa, com o objetivo de avaliar as popula??es de microrganismos, as perdas de mat?ria seca, a composi??o bromatol?gica e as caracter?sticas fermentativas de silagens mistas de capim-marandu, com diferentes n?veis de amendoim forrageiro (0; 25; 50; 75 e 100%), com e sem inoculante microbiano Sil All (Alltech do Brasil). Utilizou-se o esquema fatorial 5 x 2 (cinco propor??es de amendoim forrageiro, com e sem inoculante), no delineamento inteiramente casualizado, com tr?s repeti??es. O material foi ensilado em baldes com capacidade de 20 L, providos com v?lvulas de Bunsen, e abertos 60 dias ap?s o fechamento para as avalia??es. Observou-se efeito da intera??o n?vel de amendoim forrageiro e inoculante microbiano sobre pH (P<0,05) e teores de FDNcp (P<0,01), ?cidos l?tico, propi?nico e but?rico, popula??es de fungos + leveduras (P<0,05), produ??o de gases (P<0,01), recupera??o e produ??o total de mat?ria seca. Verificou-se efeito do n?vel de amendoim forrageiro para o pH (P<0,01) e teores de MS, PB, FDA, NIDA, lignina, FDNcp, carboidratos sol?veis residuais, NH3 (P<0,05), ?cidos l?tico (P<0,01), ac?tico, propi?nico e but?rico, popula??es de bact?rias ?cido l?tico (P<0,05) e fungos + leveduras (P<0,01) e sobre a recupera??o e perdas totais de mat?ria seca. O efeito do inoculante foi observado sobre o pH (P<0,01), teores de NIDA, lignina, FDNcp, carboidratos sol?veis residuais (P<0,05), ?cidos l?tico (P<0,01) e propi?nico, e sobre recupera??o e perdas totais de mat?ria seca. Conclui-se que, a adi??o de amendoim forrageiro ao capim-marandu, no momento da ensilagem, aumenta o teor de prote?na bruta e reduz o teor de fibra, bem como proporciona perfil fermentativo adequado e boa recupera??o de mat?ria seca nas silagens. O uso do inoculante microbiano n?o apresenta benef?cios em rela??o ? composi??o bromatol?gica, mas proporciona melhor perfil fermentativo. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Zootecnia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2013. / ABSTRACT The study was conducted at the Federal University of Vi?osa, in order to assess the populations of microorganisms, losses of dry matter, chemical composition and fermentation characteristics of silage mixed Marandu grass with different levels of peanut (0, 25 , 50, 75 and 100%), with and without inoculant Sil All (Alltech Brazil). We used a 5 x 2 factorial design (five proportions of peanut, with and without inoculation), in a completely randomized design with three replications. The material was ensiled in buckets with a capacity of 20 liters, fitted with Bunsen valves, and open 60 days after closing for evaluations. We observed a significant interaction between level of peanut and inoculation on pH (P <0.05) and levels of NDF (P <0.01), lactic acid, propionic and butyric acids, yeast fungus populations + (P <0 , 05), gas production (P <0.01), recovery and total production of dry matter. There was no effect on the level of peanut for pH (P <0.01) and DM, CP, ADF, NIDA, lignin, NDF, residual soluble carbohydrates, NH3 (P <0.05), lactic acid ( P <0.01), acetic, propionic and butyric acids, lactic acid bacteria population (P <0.05) + yeasts and fungi (P <0.01) and for total recovery and losses of dry matter. The effect of inoculum was observed on the pH (P <0.01) levels of NIDA lignin, NDF, residual soluble carbohydrates (P <0.05), lactic acid (P <0.01) and propionic, and on Total recovery and losses of dry matter. We conclude that the addition of the peanut Marandu grass at the time of ensiling increases the protein content and reduces the fiber content as well as provides adequate fermentation profile and good recovery of dry matter in the silage, regardless of the use of inoculant.
6

Res?duo ?mido de Cervejaria na Alimenta??o de Cabras. / Use of Wet Brewery Residue for Lactating Goats.

Silva, Viridiana Basoni 14 February 2007 (has links)
Made available in DSpace on 2016-04-28T14:59:46Z (GMT). No. of bitstreams: 1 2007 - Viridiana Basoni Silva.pdf: 2120660 bytes, checksum: 288bfedc4575c16c602010bb3ef36609 (MD5) Previous issue date: 2007-02-14 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This work was accomplished with aim of evaluate intake and apparent digestibility of nutrients, nitrogen balance, feeding behavior and water balance in lactating goats, fed with diets contend different levels of substitution of the concentrate by wet brewery grains (WBG): 0, 25, 50, 75 and 100%. Five goats Boer x Saanen and five Saanen goats were randomly assigned in two 5x5 Latin squares. The five experimental periods had duration length of 15 days, 10 for adaptation and five days for data and sample collections. The roughage used was tifton hay, in roughage:concentrated rate of 60:40. The animals were allocated in metabolic cages, fed twice a day. For the feeding behavior the feeding times (FT), idle time (IT) and rumination time (RT) were evaluated for each animals every 20 minutes during 24 hours. The dry matter intake (DMI), organic matter (OMI), crude protein (CPI), ether extract (EEI) neutral detergent fiber (NDFI) and total digestible nutrients (TDNI) in g/d and dry matter intake body weight (DMI BW) and neutral detergent fiber intake body weight (NDFI BW) had quadratic effect, diets more consumed were the with levels of substitution of 0 and 25%. The apparent digestibility of the dry matter (DM), organic matter (OM) and total carbohydrate (CT) decreased with linear effect with the increase of the levels of WBG in the diet and the digestibility of CP it had quadratic effect, increasing digestibility to the level of substitution of 25% of WBG of concentrate. The nitrogen balance had decreased linear effect lesser with increasing WBG. The feeding times (FT) and idles times (IT), weren t affected by increasing of levels of WBG in the diet, however, the rumination times and total chewing time had growing linear effect with increase of levels of WBG in the diet. The alimentary efficiency (ALE) and rumination efficiency (RUE) in DM/h had decreasing linear effect with increase of WBG in the diet, but when ALE NDF/h obtained a quadratic effect where larger efficiency were observed in the diets with 50% of WBG, RUENDF had decreased linear effect with increase of levels of WBG. The water balance was also influenced by the increase of the levels of WBG in diet, where larger intakes and excretions were obtained by animals that intake diet without WBG in its composition. Increases of levels of WBG decreased intake and excretions of water. It can be concluded the at diet can be used up to 50% of replacing of concentrate in the diets of lactating goats. / Este trabalho foi realizado com o objetivo de avaliar o consumo, a digestibilidade aparente dos nutrientes, o balan?o de nitrog?nio, comportamento alimentar e balan?o h?drico em cabras lactantes, alimentadas com dietas contendo diferentes n?veis de substitui??o do concentrado por res?duo ?mido de cervejaria (RUC): 0, 25, 50, 75 e 100%. Foram utilizadas cinco cabras mesti?as Boer x Saanen e cinco cabras Saanen distribu?das em dois quadrados latinos 5x5. Os cinco per?odos experimentais tiveram dura??o de 15 dias, sendo 10 de adapta??o e cinco dias de coleta de dados e de amostras. O volumoso utilizado foi o feno de tifton, na rela??o volumoso: concentrado de 40:60. Os animais foram alojados em gaiolas metab?licas, alimentados duas vezes ao dia. Na avalia??o do comportamento alimentar foram medidos os tempos dispendidos com alimenta??o, tempo de rumina??o e tempo de ociosidade que foram avaliados por observa??es dos animais a cada 20 minutos at? completarem 24 horas. O consumo de mat?ria seca em kg e em porcentagem do peso vivo (% PV), mat?ria org?nica, prote?na bruta, extrato et?reo, carboidratos totais e nutrientes digest?veis totais em g/d e fibra em detergente neutro em gramas e %PV, apresentaram resposta quadr?tica, onde as dietas mais consumidas foram a sem inclus?o de RUC e com n?vel de substitui??o de 25%. Observou-se resposta linear decrescente para a digestibilidade aparente da MS, MO e CT de acordo com o aumento dos n?veis de RUC na dieta e resposta quadr?tica para digestibilidade da PB , onde maior digestibilidade ocorreu na dieta com n?vel de substitui??o de 25% de RUC. O balan?o de nitrog?nio obteve resposta linear decrescente com o aumento de RUC na dieta. O tempo gasto com alimenta??o (TA) e com ociosidade (TO), n?o diferiram (P>0,05) quanto aos n?veis de RUC na dieta, no entanto, resposta linear crescente foi observada para os tempos dispendidos com rumina??o e com a mastiga??o total, com o aumento dos n?veis de RUC na dieta. A efici?ncia alimentar (EAL) e a efici?ncia de rumina??o (ERU) expressas em MS/h obtiveram resposta linear decrescente com o aumento de RUC na dieta, mas quando expressas em FDN/h a EAL obteve resposta quadr?tica onde maiores efici?ncias foram observadas nas dietas com 50% de RUC, a efici?ncia de rumina??o expressa em FDN/h apresentou resposta linear, diminuindo ? medida que aumentavam os n?veis de RUC. O balan?o h?drico tamb?m foi influenciado pelo aumento dos n?veis de RUC na dieta, onde animais que consumiram as dietas com 0% de RUC apresentaram maiores consumos e excre??es. ? medida que aumentaram os n?veis de RUC, menor foi o consumo e excre??o de ?gua. Concluiu-se que o RUC pode ser utilizado em at? 50% de substitui??o do concentrado na dieta de cabras lactantes.
7

Aduba??o nitrogenada em mandioca (Manihot esculenta Crantz): efeitos sobre o crescimento da cultura / Nitrogen fertilization in cassava (Manihot esculenta Crantz): effects on crop growth

SOUZA, Eva Aparecida de 29 September 2000 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2016-10-25T19:13:03Z No. of bitstreams: 1 2000 - Eva Aparecida de Souza.pdf: 524982 bytes, checksum: e193e5f67e0c9dafb75bc879a9949011 (MD5) / Made available in DSpace on 2016-10-25T19:13:03Z (GMT). No. of bitstreams: 1 2000 - Eva Aparecida de Souza.pdf: 524982 bytes, checksum: e193e5f67e0c9dafb75bc879a9949011 (MD5) Previous issue date: 2000-09-29 / Cassava (Manihot esculenta Crantz) is one of the main sources of carbohydrates for human food in the tropics, part of the staple food of about 500 million people, mainly in developing countries. The literature on cassava nitrogenous fertilization is scarce. This study aimed to evaluate the effects of levels and nitrogenous fertilizer sources on dry matter and nitrogen accumulation in roots and aerial parts of cassava. The experiment was conducted at the Experimental Station of Itagua?/PESAGRO-Rio in Serop?dica, State of Rio de Janeiro, on a Red-Yellow Podzolic soil, in the period May 1999 to June 2000. The design of the field experiment was in randomized blocks with four repetitions, in a 3 x 5 factorial outline, made up of by three N sources (urea, nitrocalcium and ammonium sulphate) and five N levels (0, 60, 120, 180 and 200 kg N ha-1). Each plot had 64.0 m2 with 12 grooves, spaced at 1.0m. The planting was carried out on 28/05/1999 with cuttings of cultivar Saracura. The nitrogen levels were divided into two applications, the first half was applied planting and other half was applied 9 month later. Plants were harvested at 07, 11 and 13 months after planting and determined dry matter, total nitrogen, nitrate-N, amino-N, crude protein and soluble sugars in roots, leaves and stem. To 7 months after planting, urea showed higher total dry matter value. At 13 months, nitrocalcium and ammonium sulphate provided dry matter root yield 20 % higher than the urea. The N content in leaves was approximately 7 times bigger those the N root contents. The application of 30 kg N ha-1 resulted in increase of 11% in leaf N content. There was a cassava response to N application and can behave as a specie efficient responsive little. / A mandioca ? uma das principais fontes de carboidratos nos tr?picos, fazendo parte da alimenta??o b?sica de cerca de 500 milh?es pessoas, principalmente em pa?ses em desenvolvimento. Estudos com aduba??o nitrogenada em mandioca s?o escassos. O presente trabalho objetivou-se avaliar o efeito de fontes e n?veis de adubos nitrogenados sobre o ac?mulo de mat?ria seca e distribui??o de nitrog?nio nas ra?zes e parte a?rea da cultura da mandioca. O experimento foi instalado na Esta??o Experimental de Itagua? (PESAGRO-RJ), sobre um solo Podz?lico Vermelho-Amarelo distr?fico, no periodo de maio de 1999 a junho de 2000. Utilizou-se o delineamento de blocos ao acaso no esquema fatorial 3 x 5 com quatro repeti??es. Foram avaliadas tr?s fontes de nitrog?nio: ur?ia, nitroc?lcio e sulfato de am?nio, combinadas em cinco n?veis de aplica??o de N: 0; 60; 120; 160 e 200 kg N ha-1. Cada parcela apresentou 64 m2 com 12 sulcos, espa?ados de 1,0 m. O plantio foi realizado em 28/05/1999, usando-se manivas da cultivar Saracura, obtidas de fonte comercial da regi?o produtora de Santa Cruz, munic?pio do Rio de Janeiro. As doses de N foram aplicadas parceladamente, sendo metade por ocasi?o do plantio e a outra metade aos nove meses ap?s o plantio. Foram realizadas coletas de material vegetal aos sete, onze e aos treze meses ap?s plantio para determinar as seguintes vari?veis: massa seca, N-total, prote?na bruta, N-amino, N-nitrato e a??cares sol?veis de ra?zes, folhas e caule. Aos sete meses ap?s o plantio, a ureia apresentou maior valor de massa seca total. Aos 13 meses, nitroc?lcio e sulfato de am?nio proporcionaram rendimento de massa seca de raiz 20% superior ao da ur?ia. A aplica??o de 30 kg N ha-1 resultou em um aumento de 11% no teor de N em folhas. O teor de N em folhas foi aproximadamente sete vezes maior ao N da raiz. Durante o per?odo de crescimento da cultura, houve uma resposta da mesma ? aplica??o de N, podendo se comportar como uma esp?cie eficiente pouco responsiva.
8

Perdas por volatiliza??o de N-NH3 e avalia??o de fertilizantes nitrogenados contendo micronutrientes na cultura do milho (Zea mays) / Volatilization losses of N-NH3 and evaluation of nitrogen fertilizer containing micronutrients in maize (Zea mays)

STAFANATO, Juliano Bahiense 21 February 2013 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-04-19T20:11:40Z No. of bitstreams: 1 2013 - Juliano Bahiense Stafanato.pdf: 777062 bytes, checksum: 5c25a6af1b707f5ea33fcb9f45c94a6a (MD5) / Made available in DSpace on 2017-04-19T20:11:40Z (GMT). No. of bitstreams: 1 2013 - Juliano Bahiense Stafanato.pdf: 777062 bytes, checksum: 5c25a6af1b707f5ea33fcb9f45c94a6a (MD5) Previous issue date: 2013-02-21 / CAPES / This study aimed to evaluate the dynamics of nitrogen losses by volatilization of ammonia from urea fertilizers pelletized with different micronutrients (zinc, copper and boron), and to evaluate possible residual effect of these nutrients as well as the effect on the growth and development of corn (Zea mays) plants. The studies took place in a greenhouse at the experimental area of the Soils Department of Federal Rural University of Rio de Janeiro. The soil used in this study was sampled from surface horizon of a Fragiudult soil and had sandy texture. For testing volatilization and residual effect of nitrogen two doses (100 and 200 kg ha-1) were applied. The fertilizers were evaluated for N losses for a period of 21 days. After the period of the N losses evaluation, corn seeds were planted in the same soil, to assess the residual effect of these pelletized fertilizer containing micronutrients. After these two experiments, they were selected, among the 15 pelletized urea formulas, 9 products that showed the best results, especially those which resulted in decreasing N losses by volatilization. These products were then evaluated for their effect on growth and development of corn plants, using the variety Sol da Manh?. The amount of the micronutrient boron in the pelletized urea positively influenced the reduction of N losses by NH3 volatilization, particularly when in higher concentration (4.0% B), reducing N losses by 50% (rate of 100 kg ha-1) and 64 % (dose of 200 kg ha-1) compared to the pearly urea. In general, the pelletized urea containing micronutrients, especially B, single or associated with Zn and Cu, showed to be a promising alternative for new fertilizers, with the goal of reducingN losses by volatilization. There was no effect of the different nitrogen fertilizers application as for increasing residual N in the soil. The application of the pelletized urea containing Zn, Cu and B micronutrients, single and / or associated, increased their quantities in the soil. The largest additions of the micronutrients Zn, Cu and B in the soil, using the pelletized urea, consequently, reflected in greatest amounts of these elements in the maize plant. The addition of zinc by application of pelletized urea did not show positive effect in the growth of corn plant as expected. Possibly, due to zinc quantities in the soil sufficient to supply the plants requirement. The presence of boron in the pelletized urea influenced the accumulation of N in the plants, especially for B concentrations in the fertilizer above 2.0 %. / Este trabalho teve como objetivo avaliar a din?mica de perdas de nitrog?nio por volatiliza??o da am?nia oriundo de fertilizantes pastilhados de ureia com diferentes micronutrientes (zinco, cobre e boro), avaliando o poss?vel efeito residual destes nutrientes como tamb?m seu efeito sobre o crescimento e desenvolvimento de plantas de milho (Zea mays). Os estudos foram realizados em casa de vegeta??o localizada na ?rea experimental do Departamento de Solos da UFRRJ. O solo utilizado neste trabalho foi proveniente de um horizonte superficial de um Planossolo H?plico (textura arenosa). Para o ensaio de volatiliza??o e efeito residual foram utilizados duas doses de N (100 e 200 kg ha-1), onde os diferentes fertilizantes foram avaliados quanto as perdas de N por um per?odo de 21 dias. Ap?s o per?odo de avalia??o das perdas de N foram plantadas no mesmo solo, sementes de milho com intuito de avaliar o efeito residual destes fertilizantes pastilhados contendo micronutrientes. Ao t?rmino destes dois ensaios, foram ent?o selecionados dentre os 15 pastilhados de ureia, 9 produtos que apresentaram os melhores resultados, principalmente aqueles que resultaram em maiores redu??es nas perdas de N por volatiliza??o, que foram ent?o avaliados quanto ao seu efeito no crescimento e desenvolvimento de plantas de milho, variedade Sol da Manh?. O micronutriente boro presente nos pastilhados de ureia influenciaram positivamente na redu??o das perdas de N-NH3 por volatiliza??o, principalmente quando presente na maior concentra??o (4,0% B), reduzindo as perdas de N em 50% (dose de 100 kg ha-1) e em 64% (dose de 200 kg ha-1) as perdas em rela??o a ureia perolada. De forma geral, os pastilhados de ureia contendo micronutrientes, principalmente B de forma isolada e/ou associado com Zn e Cu demonstraram ser uma alternativa promissora de novos fertilizantes com objetivo de reduzir as perdas de N por volatiliza??o. N?o houve efeito da aplica??o dos diferentes fertilizantes nitrogenados em aumentar as quantidades residuais de N no solo. A aplica??o dos pastilhados de ureia contendo os micronutrientes Zn, Cu e B isolados e/ou associados aumentaram as quantidades destes no solo. As maiores adi??es dos micronutrientes Zn, Cu e B no solo via ureia pastilhada refletiram-se, consequentemente, em maiores quantidades destes elementos na planta de milho. A adi??o de zinco via aplica??o de ureia pastilhada n?o apresentou efeito positivo em incrementar o crescimento da planta de milho como esperado. Possivelmente, pois as quantidades de zinco no solo foram suficientes para suprir as necessidades das plantas. A presen?a de boro nos pastilhados de ureia influenciaram o ac?mulo de N nas plantas, principalmente para concentra??es de B no fertilizante acima de 2,0%.
9

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.
10

Emiss?es de N2O do solo de cana-de-a??car plantada com fungicida via solo e fertilizada com ureia / Emissions of N2O from a sugarcane soil planted with soil fungicide and fertilized with urea

Silva, Erika Caitano da 27 July 2015 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-09-26T17:06:38Z No. of bitstreams: 1 2015 - Erika Caitano da Silva.pdf: 1958258 bytes, checksum: 61fcc63494dc0f8b0966ba187b5280a0 (MD5) / Made available in DSpace on 2017-09-26T17:06:38Z (GMT). No. of bitstreams: 1 2015 - Erika Caitano da Silva.pdf: 1958258 bytes, checksum: 61fcc63494dc0f8b0966ba187b5280a0 (MD5) Previous issue date: 2015-07-27 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The objective of this study was to evaluate the efficiency of a fungicide of the strobilurin group in reducing soil N2O production, a potent greenhouse gas, and a possible positive effect on the N use efficiency by sugarcane. Laboratory studies were conducted to evaluate the effect of fungicide in soil fertilized with N on N2O emissions, as well as greenhouse and field experiments to study the fungicide as controller of urea and ammonium nitrate induction of N2O emissions and as an enhancer of fertilizer N use efficiency by sugarcane. In addition to the monitoring of soil N2O fluxes with static chambers sugarcane leaves were collected for analysis of soluble forms of N and nitrate reductase activity together with plant parameters to estimate yield and the efficiency of fertilizer N use. Laboratory tests revealed the fungicide was capable of reducing soil N2O emissions. Regardless of N source, the fungicide did not affect the analyses of enzymes and plant N fractions in sugarcane, but there was a downward trend of N2O fluxes in the soil treated with urea in the greenhouse experiment. In the field experiment, N2O fluxes were 6 to 89 ?g N m-2h-1, 24 to 795 ?g N m-2h-1 and 27 to 508 ?g N m-2h-1 respectively to the control (no added N), urea and urea + fungicide treatments, indicating that N2O emissions were reduced in approximately 30% by the fungicide. The treatment with ammonium nitrate did not induce N2O emissions from soil. There was no significant difference between treatments in all analyses of soluble fractions and enzyme activity. Based on the dimensions of stalks, sugarcane yield was estimated at 190 Mg ha-1for the control treatment (without added N) and at 238 Mg ha-1 for urea treatment. The application of fungicide had no effect on yield. The use of fungicide reduced soil N2O emissions, but does not induce greater N use efficiency by sugarcane / O objetivo deste trabalho foi avaliar a efici?ncia de fungicida do grupo das estrobilurinas na redu??o da produ??o de N2O no solo, um potente g?s de efeito estufa, al?m de poss?veis efeitos positivos na efici?ncia de uso de N pela cana-de-a??car. Foram conduzidos estudos em laborat?rio para avaliar o efeito do fungicida em solo fertilizado com N sobre as emiss?es de N2O, assim como um ensaio em casa de vegeta??o e outro em campo, onde se estudaram a ureia e o nitrato de am?nio, tratados ou n?o com fungicida, sobre as emiss?es de N2O e indicadores de efici?ncia de uso de N pela cana-de-a??car. Al?m do monitoramento dos fluxos de N2O com c?maras est?ticas, foram tamb?m coletadas folhas da cultura para an?lise das fra??es sol?veis de N e an?lise da enzima nitrato redutase, incluindo-se tamb?m a estimativa da produtividade e efici?ncia do uso de N. Os ensaios de laborat?rio mostraram que o fungicida aplicado ao solo reduz emiss?es de N2O. No ensaio em casa-de-vegeta??o, a an?lise de enzimas e fra??es de N na cana-de-a??car n?os e alteraram com o uso do fungicida, independente da fonte de N, mas houve tend?ncia de redu??o dos fluxos de N2O no solo tratado com ureia. No ensaio de campo, os fluxos de N2O foram de 6 a 89 ?g N m-2h-1, 24 a 795 N m-2 h-1 e 27 a 508 N m-2 h-1respectivamente para os tratamentos controle (sem adi??o de N), ureia e ureia +fungicida, indicando queda nas emiss?es de N2O de aproximadamente 30% no tratamento com fungicida.O tratamento com nitrato de am?nio n?o induziu emiss?es de N2O do solo.N?o houve diferen?a significativa entre os tratamentos em todas as an?lises das fra??es sol?veis e tamb?m na an?lise enzim?tica. A produtividade de colmos (TCH), estimada a partir das dimens?es dos colmos, variou significativamente de 190 Mg ha-1, no tratamento controle (sem adi??o de N), para 238 Mg ha-1, no tratamento com ureia, por?m a aplica??o do produto n?o influenciou na produ??o da cultura. O uso de fungicida reduz emiss?es de N2O, por?m n?o induz maior efici?ncia de uso de N pela cana-de-a??car

Page generated in 0.0611 seconds