Articles
Localized amendment in a medium-density olive orchard
Article number
1457_93
Pages
743 – 748
Language
English
Abstract
Conservative agricultural practices are fundamental to reducing soil and nutrient losses from continuous tillage of cultivated land.
In modern olive groves, permanent grass cover is therefore essential.
The roots of grassy herbaceous plants establish diverse communities, alternating exploration and colonization of new soil niches with abandonment of exhausted ones, which favor the accumulation of organic matter and the regeneration of soil fertility for the olive tree.
On the contrary, in bare and continuously tilled soils, the organic substance is more rapidly mineralized, and the hospitality toward the newly formed roots of the olive tree becomes increasingly limited.
To support root development and the growth of the aerial part without disturbing the natural grass cover of the olive grove, a localized fertilization system has been developed in a 20-year-old intensive orchard (6×6 m) in central Italy.
Fertilization with organic nitrogen was applied in 2 holes (diameter 20 cm), 100 cm from the trunk and 40 cm from each other.
The treatments were repeated in two successive years, rotating the holes 90° around the trunk in the second year.
The two treatments with 2 holes and 4 holes per tree (100 and 200 g of N tree-1, respectively) were compared with a non-fertilized control.
The effects on the development of the aerial and root parts were evaluated: the growth of the trunk was greater in the treated trees than in the controls in both years, with a greater effect of the double-dose treatment (4 holes), without negative effects on fruit production.
The analysis of root development showed a greater abundance of fibrous and pioneer roots of olive trees and herbaceous species within the fertilized holes than outside, in both treatments.
The treatment with a lower dose (2 holes) showed a greater number of absorbent roots than the control, even outside the fertilized hole.
It seems that the olive tree benefits from localized fertilization by exploiting fertilized niches within coenoses with herbaceous species.
Finally, to some extent, the localized fertilization functions as a starter for the occupation of neighboring unfertilized niches.
In modern olive groves, permanent grass cover is therefore essential.
The roots of grassy herbaceous plants establish diverse communities, alternating exploration and colonization of new soil niches with abandonment of exhausted ones, which favor the accumulation of organic matter and the regeneration of soil fertility for the olive tree.
On the contrary, in bare and continuously tilled soils, the organic substance is more rapidly mineralized, and the hospitality toward the newly formed roots of the olive tree becomes increasingly limited.
To support root development and the growth of the aerial part without disturbing the natural grass cover of the olive grove, a localized fertilization system has been developed in a 20-year-old intensive orchard (6×6 m) in central Italy.
Fertilization with organic nitrogen was applied in 2 holes (diameter 20 cm), 100 cm from the trunk and 40 cm from each other.
The treatments were repeated in two successive years, rotating the holes 90° around the trunk in the second year.
The two treatments with 2 holes and 4 holes per tree (100 and 200 g of N tree-1, respectively) were compared with a non-fertilized control.
The effects on the development of the aerial and root parts were evaluated: the growth of the trunk was greater in the treated trees than in the controls in both years, with a greater effect of the double-dose treatment (4 holes), without negative effects on fruit production.
The analysis of root development showed a greater abundance of fibrous and pioneer roots of olive trees and herbaceous species within the fertilized holes than outside, in both treatments.
The treatment with a lower dose (2 holes) showed a greater number of absorbent roots than the control, even outside the fertilized hole.
It seems that the olive tree benefits from localized fertilization by exploiting fertilized niches within coenoses with herbaceous species.
Finally, to some extent, the localized fertilization functions as a starter for the occupation of neighboring unfertilized niches.
Publication
Authors
V. Giorgi, M. Zucchini, M. Menna, E.M. Lodolini, D. Neri
Keywords
Olea europaea, root density, root function, sustainability, soil conservation
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