Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-10-26T11:55:50Z No. of bitstreams: 2 albert_jose_santos.pdf: 942447 bytes, checksum: 8928d3ffa6d78de8e17e1c881d37b5f7 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-10-26T11:56:41Z (GMT) No. of bitstreams: 2 albert_jose_santos.pdf: 942447 bytes, checksum: 8928d3ffa6d78de8e17e1c881d37b5f7 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) / Made available in DSpace on 2015-10-26T11:56:41Z (GMT). No. of bitstreams: 2 albert_jose_santos.pdf: 942447 bytes, checksum: 8928d3ffa6d78de8e17e1c881d37b5f7 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) Previous issue date: 2012 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG) / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / O experimento foi conduzido entre 18 de outubro de 2011 e 3 de maio de 2012, no campo experimental da Embrapa Gado de Leite, objetivando-se avaliar dois crit?rios de manejo para o pastejo intermitente em capim-marandu; sendo um com per?odo de descanso fixo e outro com per?odo de descanso vari?vel, conforme a intercepta??o de 95% da radia??o fotossinteticamente ativa (IRFA 95) e suas influ?ncias sobre a massa de forragem, a composi??o morfol?gica, as caracter?sticas estruturais e a produ??o de leite por animal e por ?rea. Em ambos os tratamentos, o per?odo de ocupa??o foi de tr?s dias, almejando-se um res?duo p?s-pastejo de 25 cm de altura. O ajuste da lota??o em fun??o dos alvos de manejo (altura de res?duo) foi feito por meio da t?cnica de ?put and take?. Para avalia??o das caracter?sticas do pasto, o delineamento experimental utilizado foi o de blocos ao acaso, com duas repeti??es de ?rea e tr?s repeti??es dentro de bloco e, para a avalia??o da produ??o de leite, as unidades experimentais utilizadas foram dezesseis vacas Holand?s x Zebu rec?m-paridas, sendo oito por tratamento, as quais foram blocadas em fun??o da produ??o de leite, dias em lacta??o, n?mero de lacta??es, peso vivo e grupo gen?tico. Os dados obtidos foram submetidos ? an?lise de vari?ncia com o PROC MIXED do SAS? e as m?dias foram comparadas pelo teste LSMEANS, ao n?vel de 5% de probabilidade. Menor intervalo entre pastejo (22,8 dias vs. 30 dias), menor altura pr?-pastejo (35,9 cm vs. 42,3 cm) e menor massa de forragem (5.506 kg/ha.ciclo vs. 7.288 kg/ha.ciclo) foram observados para o crit?rio de per?odo de descanso (PD) IRFA 95, em rela??o ao crit?rio de PD fixo. O pasto com PD vari?vel apresentou maior percentual de l?mina foliar (48,31% vs. 41,06%) e menor percentual de material morto (19,00% vs. 25,43%) na massa seca do pr?-pastejo do que o pasto com PD fixo, garantindo com esse crit?rio, maior rela??o l?mina/colmo no pr?-pastejo. Para produ??o de leite, n?o foi observado efeito de crit?rio de per?odo de descanso (14,4 kg/UA vs. 14,0 kg/UA), sendo observado apenas efeito de ciclo de pastejo sobre a produ??o de leite por animal. No entanto, para produ??o de leite por ?rea foram observados os efeitos (P<0,05) da intera??o crit?rio de per?odo de descanso e ciclo de pastejo. Para taxa de lota??o, observou-se efeito (P<0,05) da intera??o crit?rio de per?odo de descanso x ciclo de pastejo. A maior taxa de lota??o foi encontrada no crit?rio de PD IRFA 95. Na m?dia, o crit?rio de PD IRFA 95 foi superior ao crit?rio de PD fixo para a produ??o de leite por ?rea (93,5 3kg/ha.dia vs. 71,3kg/ha.dia). Pastos de capim-marandu manejados com PD baseado na IRFA 95 apresentaram menor altura pr?-pastejo e melhor rela??o l?mina/colmo do que pastos manejados com PD fixo de trinta dias. Al?m disso, ? poss?vel, com a ado??o do crit?rio de PD baseado na IRFA 95, obter maiores taxa de lota??o animal e produ??o de leite por ?rea. Assim, recomendam-se alturas de pr? e p?s-pastejo de 35 cm e 25 cm, respectivamente, para o capim-marandu. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Zootecnia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2012. / ABSTRACT The experiment was conducted from October, 18th, 2011 to May, 3rd, 2012, at the experimental field of Embrapa Gado de Leite, aiming to evaluate two management criteria for intermittent grazing of Marandu grass; one with a fixed period of rest (RP) and another with rest periods varying according to the interception of 95% of photosynthetically active radiation, and their influence on forage production, morphological composition, structural features and the milk yield per cow and per hectare. In both treatments, the occupancy period lasted three days, aiming a 25 cm residue after grazing. The adjustment of stocking in terms of management targets (residue`s heigh) was made using the technique of "put and take". To evaluate the characteristics of the pasture the experimental design was randomized blocks with two plots and three replicates within a block, and the assessment of milk production and experimental units used were 16 Holstein x Zebu cows who had recently delivered , eight per treatment, which were allocated according to milk production, days in lactation, number of lactations, body weight and genetic group. The data were subjected to analysis of variance with PROC MIXED of SAS ? and means were compared by LSMEANS test at the 5% level of probability. Shorter interval between grazing (22.8 vs. 30 days), lower pre-grazing height (35.9 vs. 42.3 cm) and lower yield of total herbage mass (5,506 vs. 7,288 kg / ha./ cycle) were observed for IRFA 95 rest period criteria (RP) relative to fixed RP criteria. The pasture with variable RP had a higher percentage of leaf blade (48.31 vs. 41.06) and lowest percentage of dead material (19.00 vs. 25.43) in the dry mass of the pre-grazing pasture than with the fixed RP, ensuring with that criteria the better relation leaf blade: stem during pre-grazing. For milk production there has not been observed effect of the rest period criteria (14.4 vs. 14.0), being only observed effect of grazing cycle on production of milk per animal. However, for milk production per area there have been observed the effects (P <0.05) of interaction of criterion period of rest and grazing cycle. For stocking rate, there was observed (P <0.05) interaction between the period of rest x grazing cycle criterion. The higher stocking rate was found in the criteria for IRFA 95 RP. On average the IRFA 95 RP mean was higher than the fixed RP criteria set for the milk yield per area (93.5 vs. 71.3). Marandu grass pastures managed with RP based on the IRFA 95 have a lower pre-grazing height and a better relation blade: stem than pastures grazed at 30 days fixed RP. Moreover, it is possible with the adoption of criteria based on the IRFA 95 RP increase stocking rate and milk production per area. Thus, heights of 35 and 25 cm are recommended for pre-and post-grazing of Marandu grass, respectively.

Made available in DSpace on 2016-04-28T14:59:42Z (GMT). No. of bitstreams: 1 2006-Roberta Cristiane Ribeiro.pdf: 1282161 bytes, checksum: 5e7174cb11915976886dd9494c3fb2d5 (MD5) Previous issue date: 2006-09-12 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In the way to improve the agronomic indexes and animal science of acting in the pastures cultivated on State of Rio de Janeiro soils, it`s needing a deeper studies to evaluate the impact of forage legumes in those ecosystems introduction. Seeking to contribute in that direction, an experiment was installed aiming at research the effects with different introduction methods of forage legumes in a pasture forage grass in monoculture. The work hypothesis was the treatments of nature chemical or mechanical that reduces the growth in the established grass, will have favorable effects on the establishment and persistence forage legume. The work was accomplished in the experimental field of Forage study, in the Institute animal science, the Universidade Federal Rural of Rio de Janeiro, from November/2003 to Abril/2005. The studied forage legumes were estilosantes cv. Campo Grande and desm?dio (Desmodium ovalifolium Wall cv. Itabela), installed into grass pasture of Brachiaria humidicola (Rendle) Schweickt. The introduction methods compared were: i) herbicide (Glyphosate, 0,75%, V/L), one day before the planting; ii) with grass mechanical cut; iii) planting in furrows and; iv) prepare soil with use of harrowing, being used a design was a randomized block, with four repetitions. The growth of the forage legumes in the several swards formed after the installation of the treatments, it was accompanied through count of the plants number and plants height, frequency estimates, absolute and relative, of grass and legume in the sward, and the Index of Leaf Area. Together, they were made evaluations of interception photosynthetically active radiation and degree of covering of the sward mixed pasture. The contribution forage legume to the production forage mass, green and dry, was done through cuts, to the 157 and 430 days after seeding. The mixed with estilosantes cv. Campo Grande didn't prosper, due the failure in the germination and or plants emergency of the forage legume. In contrast, in the mixed case between the braqui?ria and the desm?dio specie, the initial hypothesis was confirmed fully, once all the introduction methods allowed the establishment and permanence forage legume in the grass pasture. Specifically, for this associate, it was ended that to foment a fast covering of the soil, the most suitable treatments are the harrowing and weeds (mechanical cut), while to harmonize his associate, protecting the persistence of both components, the plantings in furrow and herbicide use was the most interesting alternatives. / Como forma de melhorar os ?ndices agron?micos e zoot?cnicos de desempenho das pastagens cultivadas sobre solos do Estado do Rio de Janeiro, existe a necessidade de maiores estudos para avaliar o impacto da introdu??o de leguminosas forrageiras nesses ecossistemas. Visando contribuir nessa dire??o, foi instalado um experimento objetivando pesquisar os efeitos de diferentes m?todos de introdu??o de leguminosas forrageiras numa pastagem de gram?nea forrageira em monocultura. A hip?tese de trabalho foi a de que tratamentos de natureza qu?mica ou mec?nica que reduzam o crescimento da gram?nea estabelecida, ter?o efeitos favor?veis sobre o estabelecimento e persist?ncia da leguminosa. O trabalho foi realizado na ?rea experimental de Forragicultura, no Instituto de Zootecnia da Universidade Federal Rural do Rio de Janeiro, durante o per?odo de novembro de 2003 a abril de 2005. As leguminosas estudadas foram estilosantes cv. Campo Grande e desm?dio (Desmodium ovalifolium Wall cv. Itabela), instaladas sobre pastagem de Brachiaria humidicola (Rendle) Schweickt. Os m?todos de introdu??o comparados foram: i) herbicida dessecante (Glyphosate, 0,75%, V/L), um dia antes do plantio; ii) ro?ada: rebaixamento da gram?nea, com corte mec?nico iii) plantio em sulcos e; iv) preparo do solo com uso de enxada rotativa, empregando-se um desenho de blocos inteiramente casualizados, com quatro repeti??es. O crescimento das leguminosas nos diversos doss?is formados ap?s a instala??o dos tratamentos, foi acompanhado atrav?s de contagem do n?mero de plantas e da altura das plantas, estimativas de freq??ncia, absoluta e relativa, de gram?nea e leguminosa no relvado, e o ?ndice de ?rea Foliar. Em conjunto, foram feitas avalia??es de intercepta??o de radia??o fotossinteticamente ativa e grau de cobertura dos doss?is do cons?rcio. A contribui??o da leguminosa ? produ??o da massa de forragem, verde e seca, foi feita atrav?s de cortes, aos 157 e 430 dias ap?s a semeadura. O cons?rcio com estilosantes cv. Campo Grande n?o prosperou, devido ao fracasso na germina??o e ou emerg?ncia das pl?ntulas da leguminosa. Em contraste, no caso do cons?rcio entre a braqui?ria e o desm?dio, a hip?tese inicial foi plenamente confirmada, uma vez que todos os m?todos de introdu??o permitiram o estabelecimento e perman?ncia da leguminosa na pastagem. Especificamente, para este cons?rcio, foi conclu?do que para fomentar uma r?pida cobertura do solo, os tratamentos mais indicados s?o a enxada rotativa e a ro?ada, enquanto que para harmonizar o cons?rcio, resguardando a persist?ncia de ambos componentes, os plantios em sulco e uso de herbicida foram ?s alternativas mais interessantes.

Made available in DSpace on 2016-04-28T14:59:45Z (GMT). No. of bitstreams: 1 2008 - Leandro Galzerano.pdf: 1398173 bytes, checksum: 3b9bc8540a1e5f744b54fffefe6a7828 (MD5) Previous issue date: 2008-08-05 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This work was carried out in order to obtain subsidies under the definition of strategies for nitrogen fertilization of pastures of tifton 85, based on monitoring the dynamics changes in the structure of swards. The underlying assumption was that the application of increasing levels of N is a powerful tool for that purpose. The experiment was developed over a Planosol of occurrence in the experimental field of the Universidade Federal Rural Rio de Janeiro, city of Serop?dica, Brazil, during the establishment of the pasture, between the months of October, 2006 to January 2007. Treatments consisted of four levels of N (0, 50, 100 and 150 kg N-urea. ha-1), in single application, in plots of 4 x 4 m, arranged in blocks fully randomized, with four repetitions. Together with nitrogen fertilization, the plots received 80 kg P.ha-1 and 150 kg K.ha-1, and Ca as calcareo (1.0 tn.ha-1). The variables were: frequency of occurrence of plants; height of the canopy, leaf growth and leaf area index (LAI), the interception of photosynthetically active radiation (PAR) and the production and partition of dry matter. The results showed that the frequency of occurrence, height and interception of PAR varied according to a standard logistic, whose parameters have been modified to a greater or lesser degree, by the levels of N added. Similarly, at the 87 days after planting, the LAI and the total dry matter produced, but not its partition between leaves and stems, responded to changes in N mineral available in the soil. It was concluded that the application of increasing levels of Nurea, during the establishment of grass tifton 85 was an efficient experimental strategy for the induction of quantitative changes during the development time of swards structure. / O presente trabalho foi realizado com o prop?sito de definir estrat?gias de aduba??o nitrogenada em pastagens de tifton 85, baseadas no monitoramento de mudan?as din?micas na estrutura dos doss?is forrageiros. O experimento foi desenvolvido numa ?rea de Planossolo no campo experimental da Universidade Federal Rural do Rio de Janeiro, munic?pio de Serop?dica, RJ, durante a fase de estabelecimento da pastagem, entre os meses de outubro de 2006 a janeiro de 2007. Os tratamentos consistiram de quatro n?veis de N (0; 50; 100 e 150 kg N-ur?ia.ha-1), em aplica??o ?nica, dispostos em parcelas de 4 x 4 m, arranjadas em blocos inteiramente casualizados, com quatro repeti??es. Em conjunto com a aduba??o nitrogenada, as parcelas receberam 80 kg P.ha-1 e 150 kg K.ha-1. O solo foi corrigido com 1,0 tn.ha-1 de calc?reo. As vari?veis estudadas foram: freq??ncia de ocorr?ncia de plantas; altura do dossel, crescimento foliar e ?ndice de ?rea foliar (IAF), intercepta??o de radia??o fotossinteticamente ativa (RFA) e produ??o e parti??o da mat?ria seca. Os resultados obtidos mostraram que a freq??ncia de ocorr?ncia; altura e a intercepta??o de RFA variaram temporalmente de acordo com um padr?o log?stico, cujos par?metros foram modificados, em maior ou menor grau, pelos n?veis de N adicionados. De forma similar, aos 87 dias p?s- plantio, o IAF e a mat?ria seca total produzida, mas n?o a sua parti??o entre folhas e colmos, responderam ?s varia??es do N mineral dispon?vel no solo. Foi conclu?do que a aplica??o de n?veis crescentes de Nur?ia, durante a fase de estabelecimento do capim tifton 85 foi uma estrat?gia experimental eficiente para a indu??o de varia??es quantitativas durante o desenvolvimento temporal da estrutura dos doss?is.