Navegando por Assunto "Adubos e fertilizantes"

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Acesso aberto (Open Access)
Características morfogênicas, estruturais, acúmulo de forragem e composição química de capim-massai, submetido à adubação nitrogenada
(Universidade Federal do Pará, 2016-01-29) CUNHA, Antonio Marcos Quadros; RÊGO, Aníbal Coutinho do; http://lattes.cnpq.br/4330113577933018
The objective of this study was to evaluate the morphogenic, structural, biomass accumulation and chemical composition of plants of Massai grass submitted to six nitrogen doses (0, 100, 200, 300, 400 and 600 kg of N / ha / year) in a completely randomized design, with six replications in plots of 12 m². Urea was used as the Nitrogen source, whose doses were divided in six applications during the rainy season, according to the treatments. Forage harvesting was done at a residue height of 15 cm, when the canopy intercepted 95% of the incident light at an average of five internal points on the plot with the Accupar model LP-80® canopy analyzer. Data were submitted to variance analysis and regression, the significance level was 0.05 of the linear and quadratic coefficient and the coefficient of determination. There was (p<0.05) an increase in the rates of appearance, length and leaf senescence, as we as the number of alive leaves, number of matura leaves, percentage of stems and number of grazing cycles, all of them adjusted to a linear model. In contrast, the phyllochron, the duration of the leaf's life, the leaf blade/stem ratio and the rest days decreased, also linearly adjusted. The results for the accumulation of forage per cycle, daily forage accumulation, total forage accumulation and accumulation of dry leaf mass corresponded in quadratic form (p<0.05), the increase of nitrogen fertilization means a direct effect of the nitrogen flow in the tissues. There was a positive and linear effect of the nitrogen fertilization (p<0.05) for the crude protein and organic matter content. Negative effect (p<0.05) adjuted to a linear model for the dry matter and mineral content. No effect was observed (<0.05) for neutral detergent fiber, acid detergent fiber and hemicellulose, which limit the digestion. The nitrogen fertilization favors morphogenesis, forage production and the qualitative characteristics of Massai grass.
Acesso aberto (Open Access)
Características quantitativas e qualitativas do capim-mombaça, submetido a doses crescentes de nitrogênio em clima tropical úmido – classificação AF
(Universidade Federal do Pará, 2016-02-29) OLIVEIRA, Joelma Kyone Silva de; DOMINGUES, Felipe Nogueira; http://lattes.cnpq.br/1461187309835749
The productive chain of ruminant in northern Brazil has its base sustained by forages being its management and fertilization, grasses perpetuity, extremely important for the high biological value protein final production for human intake. The study aimed to evaluate trades of Panicum maximum cv. Mombaça fertilized with increasing doses of nitrogen at Af weather conditions being this condition classified by frequent rainfall along every month of the year, so, showing no seasonality in rain scheme. There were evaluate productive trades, morphogenetic, structural and chemical of Mombaça grass in parcels. Being the experiment outlined in random blocks with six treatments (0, 10, 20, 30, 40 e 50 kg of N ha-1 aplication-1), each application performed after each cut and four repetitions, a repetition by block totalizing 24 plots and the cut done at a height of 40 cm, whenever the parcels high achieved 90 cm to be considered the time when the canopy intercepts 95% of incident light. The data were submitted to variance and regression analysis, with significance of 5% taken from the linear and quadratic coefficients of determination. Nitrogen fertilization affected (p<0,05) stretching rates, appearance, number of leaves alive by tillers and dry mass production. The forage quality was also affected by N doses (p<0,05), being the levels of CP positively affected and values of TC negatively. The fiber levels and lignin were not influenced by fertilization (p<0,05) being this result positive from the forage nutritional pint of view, once fiber and lignin high levels do not benefit consumption and cause a digestive limitation. The nitrogen provides better qualitative and quantitative results to Mombaça grass in tropical climate areas.