Maiara Aparecida Alves
Abstract:
The low fertility of Brazilian soils, combined with the use of biomass for energy purposes in short rotation crops, may lead to greater nutrient removal from the soil. Thus, the knowledge of the nutritional dynamics of these stands can allow the proper nutritional management and the maintenance of sustained forest production in these sites. The objective of this study was to evaluate the nutrient exportation of aerial biomass of eucalyptus clones at 33 months of age submitted to two thickened spacing. The experiment was carried out in a completely randomized design (DIC), in a 3 x 2 factorial arrangement, with three clones (AEC1528, I144 and GG100) and two planting spacing (3.0 mx 0.5 m and 3.0 mx 1.0). m) with three repetitions. Five trees were sampled from each plot, later the trees were felled and sectioned. In the field, samples were taken from the crown (leaves, green and dry branches) and bark discs. These samples were dried in an electric oven with forced air circulation and renewal and ground. With the ground and crown samples, a composite sample of the tree aerial biomass was used, which was used to analyze the nutritional contents of N, P, K, Ca, Mg and S. nutrients and the efficiency of nutrient utilization. Subsequently, the analysis of variance was performed, followed by Tukey's test at 5% probability of error. For tree aerial biomass, the highest P content was found for clones AEC1528 and I144, the highest macronutrient content and export were obtained for clones I144 and GG100. The smaller spacing led to higher amounts of nutrient removal from the site. The highest utilization efficiency of P occurred for I144 and GG100 clones.
