Edaphic Characteristics of Olive-Tree Areas in the Trá-Os-Montes Region (Portugal): A Map-Based Approach

Abstract

In the Trás-os-Montes Region (Northeastern Portugal), olive tree plantations cover an area of more than 70 thousand ha (near the 6 % of the regional territory), mostly planted and cultivated under traditional non-mechanised cultural systems. It is fully recognised that the olive sector contributes significantly to the regional agroeconomy, as well as to the conservation of certain typical landscapes. The purposes of this study were (i) to draw a general picture of the olive-tree plantations spatial distribution in the Trás-os-Montes Region and (ii) to identify the main soil characteristics and land qualities of areas where olive-trees are the dominant land use. Information provided by regional soil, land use and land suitability maps (1:100 000) was selected, interpreted and treated in order to achieve those objectives. Due to the small scale of maps, results have only a reconnaissance level of detail. However, they allow conclusions on the main soil/land constraints of olivetree cultivation in the region. Development of olive-tree plantations and improvement of actual management techniques have to cope with the identified constraints. For that, research contributions are of primary importance, mainly on the fields of mechanisation, soil and water conservation and soil fertility.

A conceptual framework for the assessment of multiple functions of agro-ecosystems: A case study of Trás-os-Montes olive groves

“…Ninety-five percent of the olive area is on hilly and mountainous land more than half steeper than 15% (DEASR, 2004b), and 33% is affected by erosion (de Figueiredo et al, 2002). Two soil conservation indicators were selected: (1) the percentage of area protected by a winter cover and (2) the percentage of terraced area where terraces are well-maintained.…”

Is soil erosion in olive groves as bad as often claimed?

“…Trás-os-Montes has a continental climate caused by mountain ranges in the West and South that exclude Atlantic influences. Of the 72 288 ha under olives in the region (6% of total area), 60% receives less than 600 mm yr − 1 and 90% less than 800 mm yr − 1 (de Figueiredo et al, 2002). At Mirandela (41°29′N, 7°11′W), in the centre of the olive growing region where olives occupy 19% of all land, average annual precipitation is 520 mm.…”

“…Average annual temperature is 14.1°C (January 6.1°C, July 23.6°C). Soils are less than 0.5 m deep in 76% of olive groves, and a similar share of the groves' soils has a stoniness of over 30% (de Figueiredo et al, 2002).…”

The future of olive groves on sloping land and ex-ante assessment of cross compliance for erosion control

“…The PT4 system is in the process of abandonment and not mentioned, while PT9 does not yet exist, but rather is considered as an option for the future. From these SMOPS the traditional system (PT1) associated with a low plant density, old or very old trees and low productivity is the most represented (Figueiredo et al, 2002). This system has important environmental and social functions, such as preventing fire risk, contributing to biodiversity enhancement, and complementing income for many small or very small producers (Duarte et al, in press).…”