Produtividade e valor nutritivo do capim-braquiária em sistemas silvipastoris com eucalipto e acácia adubados com nitrogênio

• Ano de defesa: 2011
• Autor(a) principal: Wendling, Ivan Jannotti
• Orientador(a): Garcia, Rasmo
• Banca de defesa: Paciullo, Domingos Sávio Campos , Oliveira Neto, Silvio Nolasco de
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Zootecnia
• Departamento: Genética e Melhoramento de Animais Domésticos; Nutrição e Alimentação Animal; Pastagens e Forragicul
• País: BR
• Palavras-chave em Português: Ureia; Radiação; Digestibilidade; Produtividade
• Palavras-chave em Inglês: Urea; Radiation; Digestibility; Productivity
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::PASTAGEM E FORRAGICULTURA
• Link de acesso: http://locus.ufv.br/handle/123456789/1788

The productivity and nutritive value of signalgrass were studied in response to cropping systems, nitrogen levels and periods of the year, with the aim of determining its adaptation under grazing in shaded conditions. The cropping systems were established with signalgrass in monoculture (SM), signalgrass with eucalyptus (SE), and signalgrass with eucalyptus and acacia (SEA). The nitrogen levels were zero and 150 kg N ha-1 year. The periods of the year comprised the autumn-winter and spring-summer. The experimental arrangement was a split-plot in which treatments were constituted in part by a factorial arrangement of cropping systems and N levels and the sub-plot, with restrictions on randomization, by the sampling periods. The design was a randomized complete block design with three replications. The grazing interval (GI) was lower (P<0.05) in pastures to SM in relation SE and SEA pastures. The tree arrangement did not influence this variable. In general, the GI in fertilized pastures was lower (P<0.05) compared to non-fertilized. In the spring-summer the GI was lower (P<0.05) compared to autumn-winter. SM pastures had higher (P<0.05) number of grazing cycles in relation to SE and SEA pastures. The tree arrangement did not influence the number of grazing cycles. The accumulation of forage (AF) was greater (P<0.05) in SM pastures in relation to SE and SEA pastures. The fertilization affected only the AF in the signalgrass in monoculture, whereas this parameter did not differ between the silvopastoral systems, regardless of the dose of N. The rate of accumulation of forage (RAF) obtained in SM pastures was greater (P<0.05) compared to the SE and SEA pastures. Regardless of the cultivation system and period of year, forage fertilized had higher (P<0.05) compared to RAF not fertilized. The tiller density (TD) of SM was higher (P<0.05) compared to the SE and SEA, regardless of time of year. However, the TD did not differ among the intercropping systems, regardless of period of year. The factors studied did not influence the leaf: stem ratio. The accumulation of dead material (ADM) was influenced only by the cultivation system. In general, SM pastures had a higher (P<0.05) compared to ADM pastures SE and SEA. The levels of nitrogen (N) and crude protein (CP) were not influenced by the factors studied. The N content was higher (P<0.05) in SM pastures in relation to fertilized SE and SEA pastures. The composition of tree species did not influence this variable, regardless of the levels of N. The CP content was higher (P<0.05) in the monoculture than in the silvopastoral systems, regardless of the levels of N. The in vitro digestibility of organic matter was not influenced by the factors studied. A similar pattern of response occurred with the content of acid detergent fiber. The content of neutral detergent fiber (NDF) was influenced only by the interaction cropping system x period of years. The NDF content of the SM, in the autumn-winter, was higher (P<0.05) compared to the SE and SEA. In the spring-summer, the NDF content was not influenced by cultivation systems. The cellulose content was influenced only by the interaction time of year x dose of N. The cellulose content of signalgrass fertilized in the autumn-winter, was lower (P <0.05) compared to non-fertilized, while the spring-summer fertilization did not influence this variable. The lignin content was not influenced by the factors studied.