Perdida de nutrimentos por la quema de la vegetacion en una sabana de Trachypogon / The losses of nutrients by fire in a savanna vegetation of Trachypogon

RESUMO

The losses of nutrients by fire were assessed in a Trachypogon savanna located in Calabozo, Venezuela. About 95 percent of the biomass, 97 percent of N, 61 percent of P, 76 percent of K and 65 percent of Ca and Mg were transferred to the atmosphere. Ash deposition returned between 21-34 percent of Mg, Ca, K and P and 0.2 percent of N. Previous data indicated that precipitation and atmospheric fixation (in the case of N) could replace the rest of N, Ca, K and Mg transferred to the atmosphere. As a consequence of frequent burning (annual or biannual), the soil of the savanna showed lower organic matter and available P and K content when it is compared with a 32 year protected savanna