Effects of Soil Type in Nutrient Amount in Eucalyptus urograndis: Macronutrients

The aim of the present study was to quantify macronutrient stock in the hybrid Eucalyptus urograndis, for different soil types in Telemaco Borba, Parana, Brazil. Sandy texture (Cambisols Inceptisols), and clayey texture (Ferralsols Oxisols) soils were selected for the study. Based on the diameter at breast height (DBH) survey of all the trees comprising each plot, 12 trees were selected per soil type for biomass sampling. The trees were sectioned at soil level and separated into: leaves, branches, stembark, stemwood, tree tops wood, tree tops bark and roots, and a representative sample of each component was collected and grounded in a Wiley-type mill for analytical determination of the macronutrients. The analyses of the experiment were performed considering a completely randomized design. The concentrations of the macronutrients in the different biomass components were significantly different in both types of soil. With the exception of calcium, in the sandy soil and calcium and magnesium in the clayey soil, which were more present in the stembark component, the other components present the highest concentration values in the leaves component. The lowest concentration values of macronutrients, both for the sandy soil and for the clayey soil, were found in the stemwood and roots components. Total nutrient stock found in the biomass, in the sandy soil was 1.65 Mg ha-1, distributed in the following order of magnitude: stemwood > root > stembark > leaves > branches > tree tops wood > tree tops bark. For the clayey soil the order was: stemwood > stembark > root > branches > leaves > tree tops wood > tree tops bark, presenting a total stock of 2.41 Mg ha-1. The highest amount of macronutrients in the biomass was found in soil with a clayey texture.