Produção e características morfogênicas da Brachiaria brizantha cv. Xaraés com adubação convencional e fertirrigação na região Leste de Minas Gerais

• Ano de defesa: 2009
• Autor(a) principal: Cunha, Fernando França da
• Orientador(a): Ramos, Márcio Mota
• Banca de defesa: Soares, Antonio Alves , Pereira, Odilon Gomes , Rocha, Wadson Sebastião Duarte da
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Engenharia Agrícola
• Departamento: Construções rurais e ambiência; Energia na agricultura; Mecanização agrícola; Processamento de produ
• País: BR
• Palavras-chave em Português: Irrigação; Pastagem; Intervalo de desfolha
• Palavras-chave em Inglês: Irrigation; Pastures; Pasture rest period
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::ENGENHARIA AGRICOLA::ENGENHARIA DE AGUA E SOLO::IRRIGACAO E DRENAGEM
• Link de acesso: http://locus.ufv.br/handle/123456789/652

The Eastern of Minas Gerais State is a traditional region in cattle, which exerts strong influence on the regional economy, with the need to develop grazing systems associated with the practice of irrigation. Experiments had been conducted in order to evaluate the forage grasses traditionally used in the region under irrigation. The results showed that the Brachiaria brizantha cv. Xaraes was the grass that best responds to irrigation in the region. Thus, it was decided intensify the research on this grass, conducting an experiment in a sub-split-plot, and plots a 2 x 2 factorial (seasons and management of fertilization), four rest periods in the subplots and six levels of fertilization in the sub-sub- plots, in a completely randomized design with four replications. The seasons were divided into the dry season (fall/winter) and rainy season (spring/summer). The rest periods were 21, 28, 35 and 42 days. The management consisted of application of nitrogen and potassium fertilizers scattered by hand (conventional) and by irrigation water (fertigation). To differentiate the dose of fertilization in the treatment fertirrigated, it was used a line-source irrigation system. The fertilization doses (FD) had a ratio of nitrogen and potassium, 1 N: 0.8 K2O and were 0% (no N and K2O), 15% (108 kg N and 86 kg of K2O), 39% (272 kg N and 217 kg K2O), 64% (451 kg N and 361 kg K2O), 83% (587 kg N and 467 kg K2O) and 100% (700 kg N and 560 kg of K2O). The parameters analyzed were the morphogenetic characteristics, dry matter yield, plant height and soil cover. It was found that in general the spring/summer season provided higher average in all morphogenetic characteristics evaluated, but the management of fertilization provided no effect on any characteristic. Increasing the dose of nitrogen and potassium has a linear increase in the leaf appearance rate (LAR), leaf elongation rate (LER) and the emerging leaf numbers (EmLN), expanded leaf numbers (ExLN) and living leaf numbers (LLN). There was linear positive response in the stem elongation rate (SER), only in the treatment of conventional management of fertilization in the fall/winter and in the treatment fertigated in the spring/summer. In relation to the effect provided by increasing the rest period, it was found no effect on EmLN; the same result was found for LER for the conventional fertilization. For the treatment fertigated, there was a linear positive response. The LAR showed in a quadratic way to increasing the fertilizer dose; this response also observed in SER in the autumn/winter, while in the spring/summer, there was a positive linear response. The LLN and ExLN responded in a quadratic in the treatment of management of conventional fertilization and season autumn/winter and there were linear positive responses in all treatments. For the parameter dry matter yield (DM), it was found that, in general, the dry season had DM yield, but on average, the yield in the autumn/winter was 75% of that obtained in the spring/summer. The management of fertilization did not influence the values of DM yield, but increasing the dose of fertilization has positive linear effect on xaraes-grass fertigated in the autumn/winter and a quadratic effect in the other treatments. The rest periods provided quadratic effect only in the treatment fertigated in fall/winter season. The xaraes-grass provided greater soil cover in the spring/summer only in higher doses of fertilizer or longer rest periods. The fertilization did not affect the soil cover, and increasing fertilizer dose provided a linear increase in soil cover by the xaraes-grass. As to the effect provided for a rest period in the forage's soil cover, there was a quadratic effect in the conventional fertilization, and a linear and positive effect in fertigated treatments. The change of seasons did not provided difference in height of the xaraes-grass in treatment with 21-day rest period. In other rest periods, were observed higher values for plant height. The fertilization managements did not influence the values of plant height, but increasing the fertilizer dose had positive linear effect on plant height. As to the effect provided by rest periods, it was quadratic the response to the treatment fertigated in spring/summer and in other treatments, it was observed that increasing the rest period increased linearly the height of xaraes-grass.