Greenhouses or protected crops include spread material (nursery), leaf and fruit strawberries, grapes, etc., cut flowers and ornamental plants in pots. These crops are protected by mini-tunnels, tunnels, shadings, multi-tunnels and glass or plastic greenhouses.
According to the technological levels, greenhouses require different investments (€/m2) and show different attitudes towards some variables, among them influence of external weather, mechanization, automation, performance and quality of productions.
In this way low-tech greenhouses, which cost less than 30 €/m2, suffer from the external weather, while poor mechanization and absence of automation lead to variable performance and quality.
Medium-tech greenhouses require more investments (30-100 €/m2) which is partly influenced by the external weather, medium mechanization, little automation and variable performance and quality.
High-tech greenhouses, finally, whose investments are higher (more than 100€/m2) are only slightly affected by the external weather, thanks to the use of mechanization and automation they guarantee excellent quality.
Protected cultivations in the world: more than 3 million hectares. Below: Protected crops in Europe: 150,000 hectares, 66,000 of whom in Spain, 34,600 in Italy, 10,200 in Netherlands.
Thus Pardossi summed up in a short scheme the relationship between crops in greenhouses and quality of the products:
- Hygienic-sanitary safety (UV-/+, film and pesticide defence, nitro control, etc.) = the product is not bad!
- Sensory profile (taste, flavour etc.) = the product is good!
- In greenhouses it is possible to practice bio-fortification, enrichment with mineral elements, which had interesting results with selenium in lettuce and tomatoes. This is another advantage of the protected crops, their nutritional values: the product is good!
- The last point is environmental (and social) sustainability
Greenhouse with zero consumption of fossil fuels.
Greenhouses in the future: from protected environments at zero consumption of fossil fuels to structures producing energy.
The market demand of quality products will determine an increase of costs of production and prices. (Source: Ralf de Ruijte, Royla Netherlands Embassy Madrid, 2003).
Contact:
Alberto Pardossi
University of Pisa
E-mail: alberto.pardossi@agr.unipi.it