Manual of techniques for sustainable mountain viticulture Josep Lluís Pérez Verdú

Terracing consists of the transformation of natural sloping land into a new profile formed by flat strips

of a certain width (terrace), connected by new slopes of a higher gradient than the original natural

slope of the land. This has two main functions: 

•

To preserve the sol and retain the water. In general, agricultural planting requires the previous clea-

ring of the land to remove any existing plant life, including roots. The soil is therefore unprotected

against erosion, which may act aggressively due to the natural slope of the land. The basic mission

of terracing is the controlled runoff of rainwater so that soil erosion is avoided as much as possible.

Furthermore, controlled runoff increases the possibilities of water infiltration to the root area of the

plant.

The loss of soil fertility may be compatible with certain viticulture practices that base grape qua-

lity on a reduction in the production capacity of the stock. However, in the cultivation systems dis-

cussed in this Manual, maintaining the soil and its fertility is important for the plant to express all

its vigour (see Chapter 3).

•

To make working the vineyard easier, particularly through mechanisation with no labour-related

risks of machinery overturning. Terraces act as flat service passageways from where all operations

involved in vineyard cultivation can be carried out (pruning, disease control, collection, etc.). Slope

maintenance work can also be carried out from the terraces. Vineyard mechanisation to increase

productivity requires a terrace width that is the minimum necessary for the corresponding agricul-

tural machinery to pass along. 

2. Vineyard terracing 

Manual of techniques for sustainable mountain viticultur

e - 9

---

2.1. Conventional terraces

Terracing involves action on the mountain that modifies the natural conditions to a greater or less

extent.

Predominance of terraced vineyards in the Priorat region

The municipality of Porrera covers an area of 2.896 ha, which is equivalent to 16.5% the Priorat

designation of origin area. The average gradient of the municipality is 46% and its altitude is

mostly between 200 m and 600 m above sea level.

60% of traditional vineyards in Porrera were abandoned between 1986 and 2003, from the 256

ha of 1986 to the 107 ha of 2003. During that same period, terraced vineyards increased from 20

ha to 291 ha, a 1,450% growth. In the more recent period between 1998 and 2003, traditional

vineyards grew barely 12% (from 95 ha to 107), whereas terraced vineyards increased by 260%,

from 111 ha in 1998 to 291 ha in 2003. This strong increase in terraced vineyards has continued

over the past four years. 

As a whole, vineyards in Porrera increased by 44% between 1986 and 2003 and 93% between

1998 and 2003. 

These figures are considered representative of the overall evolution of Priorat.

Source: R. Cots-Folch et al./Agriculture, Ecosystems and Environment 115 (2006) 88-96.

Manual of techniques for sustainable mountain viticultur

e - 10

---

Work undertaken by the University of Lleida in the Priorat region characterises the main design para-

meters of conventional terraces built over the past decade (Figure 2.1). The following is of note:

•

The width of terraces varies between 2.37 and 5.91 m, although most widths are between 2.4 and

3 m, with an average of 2.95 m, in order to be able to plant two rows of stock on each terrace with

enough space between them for machinery to pass. 

•

The gradient of the terrace slopes varies between 24º and 56º, with an average of 39.4º, in areas

with natural slopes of between 18º and 36º (32 and 73%), with an average of 29º (55%).

Figure 2.1 Average profile

of conventional terraces in

the Priorat region

Manual of techniques for sustainable mountain viticultur

e - 11

Source: Proprietary contents, based on: María Concepción Ramos et al., Sustainability of modern land terracing for

vineyard plantation in a Mediterranean mountain environment - The case of the Priorat ..., Geomorphology (2006).

6.2m

8.0m

5.1m

Fill

Cut

2.95m

(2.4 - 5.9)

39º

(24 - 56)

29º / 55%

(18 - 36) / (32 - 73)

---

Quarry effect

Quarry effect

Manual of techniques for sustainable mountain viticultur

e - 12

---

In general and synthetically, conventional terraces are built in line with a predominant criterion: the cost

of construction. More complex financial calculations are not made, which bear in mind other costs with

repercussions that may be greater in the long term (loss of useable land, terrace maintenance, low pro-

ductivity, etc.). In addition to this is insufficient environmental and landscape sensitivity, especially by

viticulture companies whose management is unfamiliar with the cultural tradition and identity of the

mountain region in question. 

This group of causes endures because there are no clear, objective and well-documented technical

recommendations to guide vine growers and construction machinery operators. 

The conventional design of terraces may lead to environmental and operational problems in vineyard

operations.

2.1.1 Environmental problems

•

Impact on the landscape

The steel natural gradient of the land, together with gentle artificial slopes and notable terrace

widths lead to very high, long slopes that tend to disrupt the harmony of the landscape. A “quarry”

effect is caused, especially when flat-land cultivation is sought to be reproduced in the mountains.

Forcing the construction of sections of straight terraces for easier vineyard control creates extre-

mely artificial polygonal profiles that do not blend into the surroundings. Furthermore, this type of

profile requires the transverse transportation of soil, making the work more difficult and expensi-

ve. 

Flat land should not be reproduced on the mountain

Manual of techniques for sustainable mountain viticultur

e - 13

---