Efeito do controle do sob coberto e da fertilização no cresci­mento e concentração de nutrientes em pinheiro bravo (Pinus pinaster Ait.)

To study the interest of controlling the understory vegetation and the addition of N, P and K on the growth and nutrient concentration in maritime pine (Pinus pinaster Ait.), a field trial was established in a 6-year old pine forest. Five treatments were tested: control (T); cutting and removal of competing vegetation (CR); cutting, removal of competing vegetation and fertilization (CRF); cutting and chipping of competing vegetation (CD); cutting, chipping of competing vegetation and fertilization (CDF). Between 2002 and 2007, growth in the CDF treatment was higher (p <0.05) than in the other treatments. The lowest growth occurred in control and/or in the CR treatment. In general, there were no differences between CD and CRF treatments. Therefore, these results point out that removal of competing vegetation should be considered only if fertilizers are added (CRF treatment) in order to avoid negative effects on pine growth. Applying fertilizers increased N, P and K concentrations only in 2002 and 2003, although the increase was not significant.