Acúmulo de biomassa e valor nutritivo de Urochloa spp. E Panicum maximum cv. Tanzânia em sistema silvipastoril

Abstract

Aiming to evaluate the biomass accumulation, the nutritional value and the response of five grasses about effect of eucalyptus rows, this study was conducted on a silvopastoral system in the region of Ivinhema, Mato Grosso do Sul. Evaluated the total dry mass, leaf dry mass, stem and sheath dry mass, dead dry matter, tillering, plant height, relative chlorophyll index, crude protein, neutral detergent fiber, acid detergent fiber, lignin and in vitro organic matter digestibility of Urochloa brizantha cv. Xaraés, Panicum maximum cv. Tanzânia, Urochloa brizantha cv. Piatã, Urochloa decumbens cv. Basilisk and Urochloa humidicola cv. Llanero in the dry and waters season of 2012/13 and 2013/14. It was observed that during 2012/13 the low forage accumulation was due to increased competition from eucalyptus, which was in the process of growth, and was aggravated by the period of water deficit in both seasons, of which U. humidicola cv. Llanero expressed lower production. In 2013/14, the grasses had greater stability in biomass accumulation, with a positive effect of the tree component, mainly in the dry season. However, no effect was observed of the trees on the grasses nutritive value, among which P. maximum cv. Tanzânia showed greater stability in crude protein content. It was concluded that the grasses were affected by the season and distance of eucalyptus rows. Among grasses, P. maximum cv. Tanzânia showed higher sensitivity to competition next to eucalyptus rows, however, offered greater accumulation of leaf blades and greater nutritional value. The Urochloa gender showed greater yield stability between the rows, especially, U. Brizantha cv. Piatã and U. brizantha cv. Xaraés by the highest yield potential.