Effect of water and nutrient supply on root distribution in an Eucalyptus globulus plantation

Poster PaperWater and nutrients were supplied to an Eucalyptus globulus plantation in a controlled experiment in west central Portugal. The trees were planted in a sandy soil at a spacing of 3x3 m. The experiment consisted of four treatments: irrigation, irrigation plus fertilization, fertilization without irrigation, and a rain fed and unfertilized control. The quantification of root biomass was carried out 13 mo after planting. When the plantation was 31 mo old, a trench was dug in the soil touncover the distribution of the roots of individual trees. In the irrigated treatments root biomass was higher than in the control and in the fertilized plots. Differences in fine and coarse root distribution along the soil profile were also observed. In both irrigated treatments roots were concentrated along tree rows, where the irrigation tubes were dripping water or water plus nutrient