Biomassa e alocação de nutrientes em plantios comerciais de Pau-rosa (Aniba rosaeodora Ducke), em duas regiões da Amazônia central

Abstract

Rosewood oil yield is directly related to the accumulation of biomass. Thus, quantification of biomass and nutrients, allocated to different tree compartments, can help to define strategies to optimize the practices related to the management of the species. The objective of this study was to investigate the allocation of biomass and nutrients in three plantations of Aniba rosaeodora, at 10, 12 and 17 years, located in the municipalities of Maués and Novo Aripuana, Amazonas State. Therefore, biomass stocks and nutrients were determined by the destructive method, 108 trees, 36 per plantation. The average total biomass did not differ significantly between the evaluated plantations, however the total biomass stock in plantation 10 (P10), 12 (P12) and 17 (P17) years was 48.83, 44.66 and 10.00 Mg ha-1, respectively. The crown compartment of these plantations stored 34.04, 23.77 and 32.17% of the total aboveground biomass. The highest concentrations of macro and micronutrients were observed in the leaf compartment and the largest stocks in the crown compartment (leaves + branches), which was equal to 334.6 kg ha-1 (59.21%) for P10, 206.81 kg ha-1 (52.33%) for P12, and 64.36 kg ha-1 (59.23%) for P17. In general, for nutrient concentrations, significant differences were observed between compartments and between plantations. In order of predominance of the stock of macronutrients in the total biomass was N>Ca> K>Mg>P in plantations P10 and P12 and N>K>Ca>Mg>P in P17 plantation. For micronutrients, the order of predominance was Fe>Mn>Zn. Considering that there was no significant difference between the average biomass of the evaluated plantations, these plantations have different characteristics as spacing, age, and site, possibly the choice of cultivation system has influenced the nutrient allocation that affected the biomass accumulation. In this sense, the cultivation system applied in the P10 site appeared to be more favorable to biomass accumulation, because a same biomass as the other plantations accumulated in a shorter time.