Articles
A LONG-TERM EXPERIMENT ON OLIVE TREE WITH NITROGEN, PHOSPHORUS AND LIMESTONE FERTILIZATION
Article number
868_41
Pages
313 – 318
Language
English
Abstract
In Portugal, a great number of olive groves are located on acid soils, with low levels of organic matter and nutrients, in particular phosphorus.
In a mature olive grove, cultivar Verdeal Transmontana, located in Mirandela, in the Portuguese region of Trás-os-Montes, a field experiment was established in order to evaluate the effect of N, P and limestone applications on the yield and some quality parameters of olive oil.
The experiment, installed on a Cambisol, was arranged into a randomized complete blocks design with three replications and eight experimental treatments resulting from a factorial design with 23 combinations of two levels of each factor.
The limestone was applied only in the first experimental year (10,000 kg ha-1) and P was applied annually, from 1987 to 1994 (0 and 34 kg ha-1 P). Nitrogen was applied annually at 94 and 188 kg ha-1 N from 1987 to 1994, changing to 0 and 78 kg ha-1 N from 1995 to 2006. In this last period, only the residual effect of limestone and P was evaluated.
Experimental results obtained from 1995 to 2006 show an increase on fruit-yield due to N and limestone applications, respectively 35% and 18% as compared with the control.
Fruit-mean weight and fruit-fat content, as well as the quality parameters of olive oil (acidity, peroxide value, specific absorbance coefficients K232 and K270, total polyphenols, waxes and total sterols), were not significantly affected (p>0.05) by fertilization.
In contrast, oxidative stability of olive oil increased with P application.
In acid soils with low levels of organic matter it is advantageous to apply limestone and N as it results in higher fruit-yield, without affecting olive oil quality.
In a mature olive grove, cultivar Verdeal Transmontana, located in Mirandela, in the Portuguese region of Trás-os-Montes, a field experiment was established in order to evaluate the effect of N, P and limestone applications on the yield and some quality parameters of olive oil.
The experiment, installed on a Cambisol, was arranged into a randomized complete blocks design with three replications and eight experimental treatments resulting from a factorial design with 23 combinations of two levels of each factor.
The limestone was applied only in the first experimental year (10,000 kg ha-1) and P was applied annually, from 1987 to 1994 (0 and 34 kg ha-1 P). Nitrogen was applied annually at 94 and 188 kg ha-1 N from 1987 to 1994, changing to 0 and 78 kg ha-1 N from 1995 to 2006. In this last period, only the residual effect of limestone and P was evaluated.
Experimental results obtained from 1995 to 2006 show an increase on fruit-yield due to N and limestone applications, respectively 35% and 18% as compared with the control.
Fruit-mean weight and fruit-fat content, as well as the quality parameters of olive oil (acidity, peroxide value, specific absorbance coefficients K232 and K270, total polyphenols, waxes and total sterols), were not significantly affected (p>0.05) by fertilization.
In contrast, oxidative stability of olive oil increased with P application.
In acid soils with low levels of organic matter it is advantageous to apply limestone and N as it results in higher fruit-yield, without affecting olive oil quality.
Authors
P.V. Jordão, M. Encarnação Marcelo, J.I. Lopes, P. Simões Lopes
Keywords
fertilization, Olea europaea L., olive oil quality, yield
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