PRELIMINARY RESULTS ON THE MINERAL UPTAKE OF SIX SWEET CHERRY VARIETIES

Research aiming to outline the effects of the termination of conventional mineral fertilization was carried out in an organic cherry orchard in southern Italy (Bari district). This work focuses on the amount of macronutrients extracted annually by cherry cultivation. Thirteen-year-old trees, grafted onto Mazzard, of three sweet cherry varieties for fresh consumption (‘B. Moreau’, ‘Ferrovia’ and ‘Stella’) and for three varieties for processing (‘Colafemmina’, ‘Droganova’ and ‘Montagnola’), were used in this experiment. For each cultivar, dry matter from winter and summer pruning, fruit and leaves were weighed. For each of these plant parts the mineral composition was analyzed to calculate the annual mineral uptake by each variety. Results indicated great variability in annual mineral extraction (kg ha^-1 year^-1) for each of the tested mineral elements, they were 39-65 for N, 6–11 for P, 16-47 for K, 26-55 for Ca and 5-9 for Mg. Data obtained provide useful information regarding trends in the uptake of macronutrients where a regular provision of minerals is lacking; it evidenced that yearly mineral extraction by the orchard is not sufficiently counterbalanced by organic fertilizers.