Produção e composição química da Brachiaria decumbens e características dendrométricas do Eucalyptus urophylla, em sistema silvipastoril sob diferentes espaçamentos

Abstract

The aim of this study was to evaluate the introduction of trees on pasture already formed on the quantitative and qualitative of the pasture and quantitative aspects of the tree in itself. The seedlings of Eucalyptus urophylla were planted in December 2007 in the east-west spacing in 3 x 2, 6 x 4 and 10 x 4 m in an already established pasture of Brachiaria decumbens. Before planting glyphosate was applied in the seedling rows. Limins and fertilization were applied soon after digging (50 and 100g/hole respectively). And after six months was held a top-dressing fertilization with 50 g of a formulated fertilizer (12-06-12). The strip of grass received to N, P2O5 and K2O (120, 100 and 60kg/ha splited in three times) from December 2008 to March 2009. The randomized block experimental design was used. In the first study, entitled “Production and Chemical Composition of Brachiaria decumbens in Silvopastoral System with Eucalyptus urophylla in Different Spacing”, four treatments were used, which were related to the three spaces planting of eucalyptus plus the control treatment (no tree) evaluated at 03/06, 04/24, 07/03 and 12/20 of 2009. The variables evaluated were forage yield, dry weight rate accumulation (DMAR), leaf/stem ratio, crude protein, neutral detergent fiber and minerals. For these evaluations, wasd the procedure GLM of SAS was used. In this procedure, repeated measures were chosen as a sub procedure. Planting spacing of Eucalyptus urophylla only affected forage yield and DMAR up to the 24 months. In the second study, titled “Dendrométric Features of Eucalyptus urophylla in Silvopastoral System Under Different Planting Spacing”, three eucalyptus spacing were used (3 x 2, 6 x 4 and 10 x 4 m) evaluated at 6, 12, 18 and 24 months. The variables analyzed were 30 cm height diameter, crown diameter, height, breast height diameter (BHD), biomass and survival. For these evaluations, statistical software system analysis of variance (SISVAR) was used. The randomized block design was used with split plot arrangement. Planting space was allocated in the plot and the months of evaluation in the sub-plot. There was a linear effect on the months of evaluation. There was no effect either or spacing or interaction between treatment and months for 30 cm height diameter, diameter crown and height. It was not observed any effect either for BHD or survival or biomass per tree when evaluated at 24 months. There was effect for biomass per hectare being 3 x 2 m the best treatament. Therefore, one may conclude that the planting spacing only affected the biomass per hectare, when evaluated up to 24 months of Eucalyptus urophylla grown in silvopastoral system.