Long term (8 years) effect of mineral and organic fertilization on peach yield and nutritional status

We evaluated, in the long term (8 years), the effect of different organic fertilization strategies on yield, fruit quality, and nutritional status of nectarine (Prunus persica var. nectarina) Stark RedGold trees grafted on GF677 peach × almond hybrid. The experiment was carried out in a commercial orchard, where since their plantation, trees were subjected, according to a complete randomized block design (4 replicates), to the following treatments: 1. unfertilized control, 2. mineral fertilization including P (100 kg ha-1) and K (200 kg ha-1) applied at planting and N (70-130 kg ha-1 year-1) split in two applications at 40 days after full bloom (60%) and in September (40%); 3. cow manure supplied at planting (10 t dw ha-1) and then, from the 4th year, at the rate of 5 t dw ha-1 per year in spring; 4. compost supplied as for Treatment 3; 5. compost applied at a rate of 5 t dw ha-1 year-1, and 6. 10 t dw ha-1 year-1, both split as described for N application in treatment 2. Compost was obtained from the domestic organic wastes (50%) mixed with pruning material from urban ornamental tree and grass management (50%) after a 3-month stabilization. Foliar and fruit mineral concentrations (evaluated in summer) and fruit quality were not affected by treatments, however yield was higher in trees fertilized with 10 t dw ha-1 year-1 of compost, compared to unfertilized control. This result indicates that leaf mineral concentration is not always related to fruit yield