NUTRIENT ALLOCATION IN EUCALYPT PLANTATIONS IN BRAZIL

Forest management practices can alter nutrient exportation front the site. The purpose of this study was to estimate nutrient contents in the aboveground biomass of eucalyptus plantations in Brazil. The influence of key climatic variables on eucalypt productivity and nutrient content was evaluated, using the database from the Reserch Programa on Soil and Eucalyptus Nutrition of the Soil Science, Departament - Federal University of Vicosa, Minas Gerais State, Brazil. Climatic characteristics were an important component of the models. In regions with low water availability the nutrient accumulation in aboveground biomass as well as biomass production were lower. The highest proportion of all nutrients (68 % N, 69 % P, 67 % K, 63 % Ca, and 68 % Mg) was accumulated in the biomass within 4.5 years after planting for harvesting after approximately 6.5 years. After 4.5 years, the potential of fertilizer response was lower. Canopy and stem bark together accounted for 65 % N, 70 % P, 64 % K, 79 % Ca, and 79 % Mg in the aboveground biomass. Debarking in the field can therefore substantially reduce nutrient exportation and contribute to a more sustainable production in eucalyptus plantations.