Capim Tanzânia, adubado ou não com nitrogênio e avaliado por analisadores de dossel forrageiro

• Autor(a) principal: Peluso, Edmar Pauliqui
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Estadual de Maringá (RI-UEM)
• Texto Completo: http://repositorio.uem.br:8080/jspui/handle/1/1686
• topic: Adubação nitrogenada; Capim-Tanzânia (Panicum maximum Jacq cv. Tanzânia) - Adubação nitrogenada; Analisador de dossel; Capim-Tanzânia (Panicum maximum Jacq cv. Tanzânia) - Interceptação luminosa; Capim-Tanzânia (Panicum maximum Jacq cv. Tanzânia) - Manejo do pastejo; Capim-Tanzânia (Panicum maximum Jacq cv. Tanzânia) - Morfogênese; Ciências Agrárias; Zootecnia

The Brazilian livestock production is based on grazing systems. The information generated in research about this complex soil-plant-animal system works as a source of information for the national livestock pasture to remain competitive in a sustainable way. In this context, the aim of this study was to evaluate productive characteristics and nutritional value of Tanzania grass (Panicum maximum cv Tanzania), fertilized or notwith nitrogen and evaluated by canopy analyzers under intermittent grazing. The experiment was conducted at the Experimental Farm of Iguatemi - UEM, between November 2012 and January 2014. For mass production, morphological and chemical composition of Tanzania grass, a randomized block design was used, with four replicates, and the treatments nitrogen, zero, 150, 300 and 450 kg ha-1, evaluated in managed pastures light interception great (95%) obtained by Accupar Linear PAR / LAI ceptometer model LP-80 and LI-COR LAI 2000 model in times of the year: water 12/13; transition and drought; water 13/14. For morphogenetic and structural characteristics of the pasture, light interception was obtained by LAI 2000 using split plot. Nitrogen fertilization provided better composition of the canopy in all ages, mainly by reducing the dead material content. The daily and the total dry matter accumulation was found in fertilized treatments, with significant differences in favor of doses 300 and 450 kg ha-1 N in transition and drought. The addition of N improved CP content at all times. For NDF and digestibility the nutrient had a positive effect on the transition and drought periods, not influencing the ADF. The times did not influence the SER and NLL. However, they influenced LFL, Phyllochron (zero treatment) and LER (300 and 450 kg N ha-1), being the best values of the last two characteristics to water 12/13. The LFL was higher in thetransition and drought only in the control treatment. The N improved all morphogenetic characteristics except LFL, which showed no effect of the addition of the nutrient. The leaf angle and the pre grazing height were lower in water 12/13 and higher in the water13/14, with intermediate values at the transition and droughtperiods. The LAI was higher in water 13/14. The N reduced pre grazing height at all times, leaf angle in the water 12/13 and transition and dried age, and the LAI just in water 12/13. The point at which the canopy features 95% of light interception is dynamic, mainly due to N. Tanzania grass fertilized with N must be managed with pre grazing height around 60 cm. The management by LAI 2000 provided better morphological and chemical composition as well as higher mass forage production. The Accupar was ineffective to evaluate grazing in a condition of low N availability. In latitudes similar to 23°, evaluating the Tanzania grass (upright growth habit of grass), the use of LAI 2000 should be prioritized.