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: 6 6.1 DRYSTONE MASONRY STRUCTURES
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SUPPORTING
STRUCTURES.
RETAINING WALLS
Marges or terrace walls are drystone
walls which are used to create and
hold in a flat or slightly sloping area
which is normally used for farming
and called a marjada (terraced field)
and bancal in the past.
These walls are some of the most
outstanding drystone masonry features
in Majorca, especially in the
"Serra de Tramuntana" where they
have made it possible to farm the slopes
of the mountains. The first references
date from the 13th century and
are a constant feature in documents
related to farms in the island. The
importance of these wall is quite clear
since the large area they occupy; A
study of the terraced fields in 15 municipalities
in the "Serra de Tramuntana"
shows that these constructions cover
169.627 km2 which means some
17, 134 km of terrace walls.
The need to prepare sloping farmland
to deal with the danger of erosion
explains why there are so many
of them, but the process of tilling new
land and building terrace walls was
boosted over the centuries by a number
of factors: particularly the high
return on some crops, such as olive
oil and wine; the use of marginal land
through the rotes system (a long-term
rent contract for land in return for tilling
it for the first time and thereafter in
exchange for part of the harvest); tax
exemptions for some crops (as in the
case of vines in Banyalbufar in the
16th century); the division of common
land into plots, such as the small olive
groves at s'Estret d'Alaro and the Caimari
rotes which were carved out of
common land in the 17th and 19th
centuries respectively; the dividing up
of large estates which lead to the
creation of numerous farms at the end
of the 19th century and at the beginning
of the 20th; and the money spent
by returned emigrants between the
end of the 19th century and the
beginning of the 20th.
The promotion of these structures to
improve agricultural development on
the island was begun in the 18th century
with the Societat Economica d'Amics
del Pais del Regne de Mallorca
(Economic Society of Friends of the
Country of the Kingdom of Majorca),
founded in 1778 by governmental
decree. The idea was to improve traditional
crops (olive trees and vines),
to introduce new ones which were not
then well established (carob and
almond trees), and to renovate agricultural
techniques and introduce
new irrigation systems. The spreading
and promotion of innovation and techniques
at that time included the construction
of terraced fields and drainage
regulation.
Building techniques would seem to
have improved from then on and thoroughly
worked facings became more
frequent. In the second half of the
19th century an important qualitative
step was taken with the roads in the
"Serra de Tramuntana" which led to
the spreading of the technique of
polygonal retaining walls and to bigger
walls, reaching their climax in the
sa Regata retaining wall which is 17m
high and 1800 m2 in area.
Along the same lines of agricultural
improvement, a Tratado de Agricultura
(Treatise on Agriculture) was published
in the island in 1903 which specifically
mentions the need to clear the
fields of stones and to terrace the land
to prevent soil being washed away by
the rain.
The expansion of agriculture and
hence of terraced fields continued up
to the start of the 20th century, even
though the process of abandoning
land giving a marginal return on the