Agriculture Reference
In-Depth Information
Photo 14.1.
Venlo-type glasshouse, characteristic of production in the 'Dutch agrosystem'.
increase in their technological level using
well-equipped greenhouses. To find a good
economic compromise between high invest-
ments in greenhouse structures and equip-
ment and their productive performance
requires different approaches, according to
the local technical and socio-economic
characteristics, to produce high quality
vegetables competitively (Castilla, 2002).
Table 14.1.
Average construction cost of the
greenhouse structures in the south of Spain
(excluding taxes). Values calculated for a minimum
surface of 1 ha, including the installation of a
plastic film cover (year 2007).
Greenhouse type
Cost (
€
m
−2
)
Low-cost parral-type greenhouse
(motorized sidewall and roof
ventilation)
Low roof slope (old type)
10.0
High roof slope (27°/27°)
14.0
14.1.2
Greenhouse structures
and equipment
Multi-tunnel greenhouse, with
motorized sidewall and roof
ventilation
19.0
The choice of a certain greenhouse structure
carries with it the choice of technological
equipment in agreement with the chosen
structure, so that the 'technological pack-
age' (the set of greenhouse and equipment)
allows for achieving the right agronomic
performance at a given cost.
Table 14.1 presents the average con-
struction costs of the most usual structures
in southern warm climates. The cost of
the multi-tunnel-type greenhouse structure
with a curved-shape cover duplicates that
of a low-sloped roof low-cost greenhouse
(common in Spain).
Among the different equipment choices
for these structures, Table 14.2 presents
some of the possibilities, incorporating in
the case of the improved low-cost green-
house a set of de-stratification fans and the
cheapest fog and heating systems. In the
more expensive multi-tunnel greenhouse
structure (Photo 14.2), better fog and heat-
ing systems are implemented, as well as
thermal and shading screens. Obviously,
the specific choice of the equipment
depends on the prevailing conditions; the
example in Table 14.2 only aims to illustrate
the level of investment for a certain 'techno-
logical package'. Therefore, the simplest
case of low-cost 'parral-type' greenhouse
