Nitrogen Application in a Two-Year-Old Cherry Orchard on Gisela® 6: Effects on Biomass Accumulation, Nitrogen Uptake and Partitioning

An experimental orchard of 'Bing' sweet cherry (Prunus avium L.) on a semivigorous rootstock, Gisela(R) 6, was planted in August 2006 in Chile's central region, at a density of 890 tree ha(-1). The objective of the study was to evaluate the effects of nitrogen (N) fertilization on biomass accumulation and N uptake, as well as their partitioning among tree components during the second growing season after establishment. Beginning the planting year, three N rates (0, 60, and 120 kg ha(-1)) were applied in a four-replicate completely randomized design. At the end of the first and second growing season, four trees per treatment were harvested to determine dry weight and N concentration in different tree components. Total biomass accumulated varied between 1,647 and 2,233 kg dry matter ha(-1). However, there were no differences between treatments neither in total biomass nor in individual tree organs. Slight effects on N uptake in individual tree components were observed and no significant differences among N treatments were detected for total N uptake, although this ranged between 25 and 34 kg N ha(-1). These results indicate that the original soil supply was sufficient to meet the N requirements of the trees. Biomass and N accumulated during two growing seasons was mainly distributed to main roots and wood. Our results suggested that the young non-bearing cherry trees on semi-vigorous rootstock had a low apparent N recovery efficiency (<15%) and a low N demand (about 18 kg N ha(-1)).