Articles
ASSESSMENT OF NUTRIENT OUTPUTS IN CHESTNUT GROVES: FRUIT AND PRUNED BIOMASS
Article number
815_10
Pages
75 – 82
Language
English
Abstract
Within the Trás-os-Montes region, NE Portugal, chestnuts are one of the few marketable crops that farmers have.
So, in the last years, management practices have been intensified in order to increase fruit production.
The higher production leads, naturally, to an increased nutrient output.
Results obtained in seven groves, between 1991 and 2000, showed that, on average, each ton of chestnut fruit dry matter exported 9.8 kg of N, 8.4 kg of K, 1.5 kg of P, 1.1 kg of Ca, 0.7 kg of Mg, 0.6 kg of S, 126 g of Mn, 43 g of Fe, 15 g of Zn and 9 g of Cu.
Another major pathway for nutrient output is the removal of pruned biomass.
From 1991 to 2000, the nutrient amount in the different components of pruned material (leaves, burs, flowers, twigs and branches) was quantified.
The results showed that, on average, each ton of pruned material contains 4.6 kg of Ca, 3.6 kg of N, 2.3 kg of K, 0.7 kg of Mg, 0.6 of P, 0.4 kg of S, 237 g of Mn, 54 g of Fe, 23 g of Zn, and 2.9 g of Cu.
Since 50% of these nutrients were in the leaves, burs, flowers and twigs which, on average, represented only 26 % of the total pruned biomass, the nutrient output could have been minimized if the finer material stayed in the field.
In relation to Ca, however, it would be difficult to decrease the exportation because this element is mainly concentrated in the bark of thicker branches.
So, in the last years, management practices have been intensified in order to increase fruit production.
The higher production leads, naturally, to an increased nutrient output.
Results obtained in seven groves, between 1991 and 2000, showed that, on average, each ton of chestnut fruit dry matter exported 9.8 kg of N, 8.4 kg of K, 1.5 kg of P, 1.1 kg of Ca, 0.7 kg of Mg, 0.6 kg of S, 126 g of Mn, 43 g of Fe, 15 g of Zn and 9 g of Cu.
Another major pathway for nutrient output is the removal of pruned biomass.
From 1991 to 2000, the nutrient amount in the different components of pruned material (leaves, burs, flowers, twigs and branches) was quantified.
The results showed that, on average, each ton of pruned material contains 4.6 kg of Ca, 3.6 kg of N, 2.3 kg of K, 0.7 kg of Mg, 0.6 of P, 0.4 kg of S, 237 g of Mn, 54 g of Fe, 23 g of Zn, and 2.9 g of Cu.
Since 50% of these nutrients were in the leaves, burs, flowers and twigs which, on average, represented only 26 % of the total pruned biomass, the nutrient output could have been minimized if the finer material stayed in the field.
In relation to Ca, however, it would be difficult to decrease the exportation because this element is mainly concentrated in the bark of thicker branches.
Publication
Authors
A.L. Pires, E. Portela
Keywords
Macronutrients, micronutrients, mineral nutrition, mineral depletion
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