Responses over four years to fertilization of secondary forest growth following pasture abandonment in central Amazonia
Ted
R.
Feldpausch, Cornell University, trf2@cornell.edu
(Apresentador)
Susan
J.
Riha, Cornell University, sjr4@cornell.edu
Erick
C.M.
Fernandes, Cornell University, ecf3@cornell.edu
Elisa
Vieira
Wandelli, Embrapa Amazônia Ocidental, elisa@cpaa.embrapa.br
Secondary forests on abandoned pastures in the Amazon Basin are growing predominately on soils that have been depleted of nutrients via logging, grazing and burning. In this study, we examined the effect of P and Ca additions to soil on the growth of 10 forests in abandoned cattle ranches by applying the nutrient treatments: +P (50 kg ha-1), P+lime (2 t ha-1), P+lime+gypsum (1 t ha-1). We studied the emergence, development and death of over 4000 stems over four years in three age classes of secondary forest (1 to 5, 6 to 10, and 11 to 14 years old. Mean woody biomass accumulation in the recently abandoned pastures was low (1.8±0.5 t ha-1yr-1) and was unaffected by fertilizer treatments. Older secondary forests, with a mean growth rate of 7.1±1.8 t ha-1yr-1 (6 to 10 years) and 7.8±2.2 t ha-1yr-1 (11 to 14 years) did not respond to the P and the P+Ca +gypsum additions. Results of this experiment are compared to similar experiments in which the same fertilizer treatments were applied to improved pastures and multipurpose tree species in the same ranches. In both cases, there was a positive growth response to fertilizer additions.
Submetido por Ted R. Feldpausch em 06-ABR-2005
Tema Científico do LBA: B (Biogeoquímica)
Sessão: B: Nutrientes na interface planta-solo-água