Influência da topografia e da fertilização fosfatada sobre o crescimento de Eucalyptus urophylla x E. grandis

Abstract

The objective of this study was to evaluate the growth of Eucalyptus urophylla x E. grandis in three different topographic positions with different planting fertilization doses. The experiment was installed in a eucalyptus plantation as a silvopastoral system, in area of Cachoeirão’s farm in Além Paraíba – MG. It was used a randomized block design with plots divided in space, the plots were at the top of the hill (site 1), in the upper third (site 2) and in the middle third of the slope (site 3), with allocation of five treatments of planting fertilization. Treatment 1 was the control (no fertilization) and treatments 2, 3, 4 and 5 with 50, 100, 150 and 200 grams of NPK (04-31-04) per hole, respectively. The site 1 was the topographic position in which was registered the highest average growth and also higher biomass of eucalyptus trees, the site 3 recorded the lowest average and site 2, intermediate averages. In topographic positions 1 and 2, in the conditions that this work was conducted, the recommended dose of fertilizer to achieve better growth of eucalyptus trees is approximately 120 grams of NPK (04-31-04) per hole. In the middle third, the optimal dose is 200 grams per hole. It is advisable that in relief conditions similar to the ones of this experiment, fertilizer recommendations should be made taking into account the position in the toposequence, due to the great influence provided by this gradient on the growth and plant responses to planting fertilization.