Growth Eucalyptus dunnii as effected by phosphorus fertilization and pulp and paper mill wastes application

Abstract

Fast growing plantations in Brazil, especially with Eucalyptus and Pinus species, are responsible for thousands of employs, presenting significant participation in the country economy. It also contributes to the environment by lowering the pressure over natural forests helping to preserve their natural resources. The extremely high growth rate of these forest plantations imposes high demand on water and nutrients from the soils in addition the majority of these soils are poor in nutrients. This is motive of wariness in relation to the sustainability of the future productivities. Replenishment of nutrients is necessary and use of wastes from pulp and paper mills, for this purpose are envisaged as a priority. In this paper it was evaluated, in a factorial designed trial, the effect of five doses of pulp and paper wastes (0, 10, 20, 40, 80 t/ha), and four doses of phosphorous as P₂O₅ (0, 28, 56, 112 g/tree). The planting was performed in the region of Ponta Grossa, state of Paraná-BR in LATOSSOLO VERMELHO-AMARELO, a chemically poor soil, very common in the so-called region of the "Campos Gerais". Trees were implanted in 3m X 2m spacing. Phosphorous were applied in furrows between the rows at planting time, and wastes ten months latter spread over the surface and mixed in the soil by a rotating tillage tool. The results obtained 6 years after planting allowed the following conclusions: application of phosphorous and pulp and paper wastes increased wood volume substantially to the control, about 38% and 61% from the smallest to the biggest dose rate of phosphorous and among 20% to 40% for pulp and paper wastes applied; increases of 52% to 92% of productivity above the control treatments were also obtained with different combinations of P and waste.