Desenvolvimento de Eucalyptus grandis x E. camaldulensis sob diferentes combinações de doses de fósforo e nitrogênio

Abstract

The agrosilvipastoris systems are represented by consortia of pastures, crops and trees or shrubs in the same area, simultaneously or over time. The aim of this study was to determine the best dose of nitrogen and phosphorus, plus the best combination of these two nutrients to Grancam Eucalyptus hybrid (E. grandis x E. camaldulensis) in its initial development, in a agrosilvipastoril system. The experiment was conducted in Unit Dairy Cattle Teaching and Research of the Federal Technological University of Paraná Campuses Dois Vizinhos - PR. The tree species used was from cloned seedlings of Eucalyptus hybrid Grancam, derived from the cross E. grandis x E. camaldulensis. The experimental design will be a randomized block design with three (3) replications, each double row of trees represents a block, considering the steepness of the terrain and conditions of soil heterogeneity. It is suggested, therefore, that phosphorus levels above 23.94 g plant-1 of P2O5 not determine a greater response in height growth of hybrid eucalyptus used and that the responses to nitrogen fertilization are dependent on the phosphate fertilizer in the soil in question. Once the soil of the region in which the study was conducted has similar characteristics with clay content above 55 % and rich in oxides, giving phosphorus retention. Possibly high doses of P in the base can deliver results if fractional application. Phosphorus levels above 23.94 g plant-1 of P2O5 not determine a greater response in height growth of Eucalyptus hybrid E. grandis x E. camaldulensis during 256 days of age. Responses to nitrogen fertilization of Eucalyptus hybrid E. grandis x E. camaldulensis are dependent of P fertilization.