Although there has been recent progresses in relation to Pinus pinea fertilization in Spain (Calama et al. 2007) there are no fertilization trials for Portuguese site conditions. Analysis of data from the irrigation and fertilization trial (task 2) and the fertilization work described under task 3, will be carried out, aiming to produce Pinus pinea management guidelines for irrigation and fertilization. Given the correlated structure of the data (repeated measurements taken on different years from trees located within plots) statistical analysis will be carried out by using multilevel mixed models, which include both fixed (fertilization, irrigation, fertilization * irrigation, tree-level covariates) and random (tree within plot, plot, year) components in their formulation. This type of analysis will allow us to obtain unbiased estimates of the effect of the evaluated treatments on tree growth and fruit production.
Results from the analysis will help to determine the economical viability of the fertilization and irrigation practices and to define possible guidelines for intensive practices in young plantations of stone pine. Together with this, these data analysis might produce new data to be included in the Pinus pinea databases which are going to be developed in task.5 as well as data useful for 3-PG calibration and validation in task.9.