CONICET | Buscador de Institutos y Recursos Humanos

With the objective of analysing the early nutrition of seedlings of native Patagonian trees, an experiment was carried out on Nothofagus nervosa seedlings growing in a nursery. Based on previous results on mature forests, we assumed that nitrogen is the limiting factor for this species (phosphorous was found not to be limiting). Plants were grown on young volcanic soils taken from N. nervosa forests with minimal disturbance, and fertilized (after one year without fertilization) with 100, 200 and 400 g N kg-1 soil, with or without a single rate of P (60 g kg-1), and compared with unfertilized (control) seedlings. Twelve months after fertilization, seedlings under intermediate N rates and P (200 N + 60 P) reached higher stem diameter, length, number of leaves and root diameter than control seedlings. Above-ground and below-ground biomass and N concentration in green leaves followed trends similar to those of the other variables, although differences among treatments were not significant for biomass and N concentration. These results suggest that, unlike our previous ideas, P might be playing an important role in the early nutrition of N. nervosa seedlings.