Nitrogen application in a two-year-old cherry orchard on GiselaReg. 6: effects on biomass accumulation, nitrogen uptake and partitioning.

摘要

An experimental orchard of 'Bing' sweet cherry (Prunus avium L.) on a semi-vigorous rootstock, GiselaReg.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).