No abstract

No abstract

No abstract

This study evaluated the forage mass, plant height, chemical composition and chlorophyll index of signal grass (Brachiaria decumbens cv. Basilisk), as well as the content of organic matter (OM) in soil under increasing levels of nitrogen. The experiment was conducted in the Rio Manso Farm, experimental unit of the Federal University of the Jequitinhonha and Mucuri Valleys -UFVJM in the municipality of Couto de Magalhães de Minas, state of Minas Gerais. For plant evaluation, we use a split plot randomized block design with four replications. Nitrogen levels (0, 25, 50, 75, 100 kg ha -1 N) were assigned to plots and the cuts made in plants, to subplots. For the assessment of soil organic matter, we used a split-split-plot, with nitrogen levels (0, 25, 50, 75 and 100 kg ha -1 by cut) in the plots, collection depth (0-10 and 10-20 cm) in the subplots and three sampling times (before the onset of the experiment, at the end of the 1 st crop year and at the end of the 2 nd crop year) in sub-subplots in a randomized block design with four replications. It can be concluded that nitrogen fertilization linearly increases forage mass, plant height and crude protein content of signal grass, which are positively correlated with chlorophyll index. At the end of two agricultural years, the content of organic matter in the soil decreases, which can be attributed to management of cutting and removal of the cut material. Key words: Height. Brachiaria decumbens. Neutral detergent fiber. Crude protein. ResumoObjetivaram-se avaliar a massa de forragem, a altura de plantas, a composição química e o índice de clorofila do capim-braquiária (Brachiaria decumbens cv. Basilisk), assim como, o teor de matéria orgânica (MO) Nas parcelas distribuíram-se as doses de nitrogênio (0; 25; 50; 75; 100 kg ha -1 de N) e nas subparcelas os cortes efetuados nas plantas. Para a avaliação da matéria orgânica do solo, utilizou-se o esquema de parcelas subsubdivididas, com as doses de nitrogênio (0; 25; 50; 75 e 100 kg ha -1 por corte) nas parcelas, profundidade de coleta (0-10 e 10-20 cm) nas subparcelas e os três momentos de amostragem (antes do início do experimento, ao final do 1º ano agrícola e ao final do 2º ano agrícola) nas subsubparcelas, no delineamento em blocos casualisados, com quatro repetições. Com base nos resultados obtidos, conclui-se que a aplicação de nitrogênio aumenta linearmente a massa de forragem, a altura de plantas e o teor de proteína bruta do capim-braquiária, os quais apresentam correlação positiva com o índice de clorofila. Ao final de dois anos agrícolas, o teor de matéria orgânica no solo decresce, o que pode ser atribuído ao manejo aplicado, de corte e remoção do material cortado. Palavras-chave: Altura. Brachiaria decumbens. Fibra em detergente neutro. Proteína bruta.

The study evaluated chemical composition, fermentation profile, microbial population and dry matter recovery of silages made from mixtures of palisade grass (Urochloa brizantha cv. Marandu) and forage peanut (Arachis pintoi cv. Belmonte). The experiment was conducted and analyzed in a complete randomized factorial design using 5 levels of each forage (0, 25, 50, 75 and 100% on a fresh matter basis), with and without microbial inoculant and 3 replications. The crude protein concentration increased linearly (P<0.05) and fiber concentration decreased linearly (P<0.05) as forage peanut level in silage increased. There was a positive quadratic effect (without inoculant) and positive linear effect (with inoculant) on lactic acid concentration (P<0.05) and a positive quadratic effect (P<0.05) on lactic acid bacteria population with increasing forage peanut levels in silage. The main effects of the addition of forage peanut to palisade grass at ensiling were improvement in the chemical composition and fermentation profile of the grass silage. We recommend adding 25–75% forage peanut to palisade grass prior to ensiling to improve the quality of the resulting silage but there is little merit in adding microbial inoculant to the forage at ensiling. Feeding studies with animals would verify potential benefits in production from inclusion of legume with grass at ensiling, while studies with addition of energy sources at ensiling would determine any further benefits to be achieved in silage quality.