[en] Despite its economic importance, there are few studies on the fertilization needs of eucalyptus in Galicia. For this reason, the objective of this work was to determine the effect of increasing amounts of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), boron (B), as well as the absence or presence of other microelements (M0) in the fertilization treatment, on the growth of Eucalyptus nitens over five years, using diameter at breast height and volume as study variables. This research was conducted in a tree plantation in the region of A Mariña (North of the Lugo province). For the field trials, three areas close to each other were selected, in each of which 14 plots were prepared with a sample size of at least 32 plants each. Each plot was exposed to one of the fertilization treatments, which included four doses of N, P and K, two doses of B (addition or no addition), and two doses of micronutrients (addition or no addition). At the beginning of the study, soil and leaf samples were collected to analyze their composition. Plant growth was monitored for 5 years, using a digital caliper to measure diameter at breast height, and a laser hypsometer to measure height. Periodic measurements were made every 6 months during the first year, and annually during the rest of the study period. Plant volume was calculated with a dasometric model using diameter and height as independent variables. The measurements of the diameter and initial volume were subjected to the Shapiro-Wilks Normality Test using the statistical package EPIDAT v 4.0. Student's t-test was applied to compare means, and contrasts were carried out to assess the effect of each treatment against the standard fertilization and a control without fertilization, expressed as differences in initial and final diameters, as well as differences in volumes. A mixed linear model was applied to evaluate the effect of the treatments on the analyzed variables. The significance level for all tests was p<0.05. The soils of the three zones are acidic, with a sandy-loam texture, although with different clay content, organic matter content, and C/N ratio, which could influence nutrient availability in each zone. Statistically significant differences were observed with increasing doses of NPK compared to the fertilization considered standard and to the control (without the addition of fertilizers). In zone 3, this effect was more significantly observed, with an increase in growth when nitrogen and phosphorus doses increased compared to standard fertilization. No general best fertilization treatment could be defined for the three areas. The main conclusions drawn from the results were: 1. In all cases, the treatment without fertilization (TT) showed limited growth compared to any of the other treatments in the three zones, although only in one of them were these differences statistically significant. 2. There was no evidence of a treatment with a stronger response in final diameter and final volume for all zones, but optimal fertilization depended on the zone in which the trial was carried out. 3. In zone 3, the treatments with the highest doses of N and P showed greater growth tan the rest of the applied treatments. 4. A greater response was observed with the standard fertilization treatment in all the zones, expressed in an increase in diameter, although no statistically significant differences were found with all the treatments. 5. The effect of the different fertilization treatments on the volume was not significant, due to the high intra-treatment variability observed for this variable.

[gl] Malia a súa importancia económica, son poucos os estudos sobre as necesidades de fertilización do eucalipto en Galicia. Por este motivo, o obxectivo deste traballo foi determinar o efecto de cantidades crecentes de nitróxeno (N), fósforo (P), potasio (K), calcio (Ca), boro (B), así como a ausencia ou presenza doutros microelementos (M0) no tratamento de fertilización, sobre o crecemento de Eucalyptus nitens ao longo de cinco anos, utilizando o diámetro á altura do peito e o volume como variables de estudo. Esta investigación realizouse nunha plantación forestal da comarca da Mariña (N da provincia de Lugo). Para os ensaios seleccionáronse tres zonas próximas entre si, en cada unha das cales se prepararon 14 parcelas cun tamaño de mostra de polo menos 32 plantas cada unha. En cada parcela aplicouse un dos tratamentos de fertilización considerados, que incluiron catro doses de N, P e K, dúas doses de B (con adición ou sen adición) e dúas doses de micronutrientes (con adición ou sen adición). Ao inicio do estudo tomáronse mostras para analizar a composición do solo e análise foliar en cada zona. Monitorizouse o crecemento da planta durante 5 anos, utilizando un calibre dixital para medir o diámetro á altura do peito e un hipsómetro láser para medir a altura. Realizáronse medicións periódicas cada 6 meses durante o primeiro ano, e anualmente durante o resto do período de estudo. O volume da planta calculouse cun modelo dasométrico utilizando o diámetro e a altura como variables independentes. As medicións do diámetro e do volume inicial foron sometidas á proba de normalidade de Shapiro-Wilks mediante o paquete estatístico EPIDAT v 4.0. Aplicouse o test t de Student para comparar medias e realizáronse contrastes para valorar o efecto de cada tratamento fronte ao tratamento de fertilización estándar e ao control, expresado como diferenzas de diámetros finais e iniciais, así como diferenzas de volumes. Aplicouse un modelo lineal mixto para avaliar o efecto dos tratamentos sobre as variables analizadas. O nivel de significación para todas as probas estableceuse en p<0,05. Os solos das tres zonas son ácidos, de textura franco-arenosa, aínda que con contidos de arxila, materia orgánica, e relación C/N diferentes, o que poderían influír na dispoñibilidade de nutrientes en cada zona. Observáronse diferenzas estatisticamente significativas entre doses crecentes de NPK en comparación coa fertilización considerada estándar e en comparación co control (sen adición de fertilizantes). Na zona 3, este efecto evidenciouse de forma máis significativa, atopándose un aumento do crecemento ao aumentar as doses de nitróxeno e fósforo en comparación coa fertilización estándar. Non se puido definir globalmente un mellor tratamento para as tres áreas. As principais conclusións extraídas dos resultados foron: 1. En todos os casos, o tratamento sen fertilización (TT) presentou un crecemento menor en comparación con calquera dos outros tratamentos das tres zonas, aínda que só nunha delas estas diferenzas foron estatisticamente significativas. 2. Non houbo evidencia dun tratamento cunha maior resposta no diámetro final ou no volume final para todas as zonas, xa que a fertilización óptima dependeu da zona na que se realizou o ensaio. 3. Na zona 3, os tratamentos con doses máis altas de N e P presentaron un maior crecemento que o resto dos tratamentos aplicados. 4. Observouse unha maior resposta co tratamento de fertilización estándar en todas as zonas, expresada nun aumento de diámetro, aínda que non se atoparon diferenzas estatisticamente significativas con todos os tratamentos. 5. O efecto dos diferentes tratamentos de fertilización sobre o volume non foi significativo, debido á alta variabilidade intratratamento observada para esta variable.