Composi??o qu?mico bromatol?gica do capim Tifton 85 e sua rela??o com os teores de clorofila

• Autor(a) principal: Silva, Rosani Val?ria Marcelina Matoso
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRRJ
• Texto Completo: https://tede.ufrrj.br/jspui/handle/tede/597
• topic: aduba??o nitrogenada; clorofil?metro; Cynodon spp; fra??es de carboidratos; fra??es nitrogenadas; chlorophyll meter Nitrogen fertilization; protein fraction; total carboydrate fractions; Zootecnia

The purpose of this work was to evaluate the nutritional value of Tifton 85 (Cynodon spp) in response to nitrogen fertilization, in terms of bromatological composition and the nitrogen and carbohydrate fractions as defined by the Cornell University model. It also assessed the performace of a chlorophyll meter, as an indirect estimate of green dry matter production, and chemical bromatological traits fo the grass. This study was carried out during the period of november 2008 to january 2009, on Haplic Planosol at the campus of the Rural Federal University of Rio de Janeiro. Experimental design was a randomized block desing with four repetitions. Main treatments consisted of N rates allocated in the plots and cutting number were allocated in the sbplots. There are three levels of N soil : low N; represented by soil N, medium N: 75 N / ha / cut, and high N: 150 kg N / ha / cut. Herbage harvested twice, the first on November 30 and the second 29 days later. Cutting dates were determined according to data from canopy light interception. In the first study results showed that N rates increased green dry matter and the crude protein CP per cent in the forage and decreased asid detergent fibrous fraction contents. It was also verified the feasibility of using a chlorophyll meter as a probe for CP content and forage availability. In a second study it was verified that N fertilization showed no consistent results in regard to crude protein fractions with the sole exception of C fraction (%CP), that increased with increasing N availability.