Agriculture sustainability is fundamentally based on the following 5 aspects: 1) policy and problem management on an economic, cultural and social level; 2) energy and production inputs: energy sources, fertilizers, crop protection from pathogenic attacks, organic agriculture, research and technology; 3) genetic resources: identification, evaluation and use; 4) climate: impact on production; 5) soil and water: available resources and crop requirements. The Protected Cultivation in a Mediterranean Climate system is currently characterized by:
· Poor knowledge of the most up-to-date techniques for greenhouse productions;
· Limited development of a specific greenhouse industry for Mediterranean areas;
· Farmers unfamiliarity with cost-benefits assessment of long-term investments;
· Limited access for farmers to long-term investment loans;
· Inadequate extension service and insufficient research actions. The perspectives and objectives for future development depend on the possibility of identifying:
· at a crop level: new species, cultivars, and propagation techniques;
· at a management level: strategies to improve an efficient use of natural resources;
· at a technological level: new materials and architectural solutions for greenhouse structures;
· at a market level: 1) novel marketing strategies and promotion of brand-names that associate Mediterranean greenhouse productions to Mediterranean high-quality produce; 2) strategies to strengthen farmers education on basic business principles. In order to achieve these objectives, investments in research and development are required in diverse areas connected to the greenhouse production system. The sustainability of these investments should be assessed based on the economic and social features of the Mediterranean greenhouse agroecosystem. The Northern European strategy for reducing the environmental impact of protected is to envision the greenhouse as a fully-controlled “closed” system, that can be managed based on 1) the reduction/reuse of waste materials and toxic residues; 2) automation and computerization; 3) pest monitoring; 4) “soilless” cultivation; 5) nutrient solution recycling. Such a high-input system is economically sustainable only for cash crops. In contrast, the Mediterranean greenhouse has evolved toward a “semi-closed” agricultural system characterized by lightweight structures and simple covering materials. This greenhouse system requires additional research on 1) thermal and optical characteristics of the covering materials; 2) introduction of new crops and cultivars suitable for Mediterranean environments; 3) farmers appreciation of new concepts such as eco-compatibility and efficient use of natural resources. Based on our analysis it was concluded that despite the necessity of improving the technology of the greenhouse Mediterranean production system, farmers from these areas should take advantage of the reputation of the more tasty and flavored Mediterranean products that are generally perceived by the consumer as a more “natural” food compared to “artificial” Northern Europe greenhouse produce. In this respect the Mediterranean produce should be presented on the market with a specific quality label (i.e. an eco-label such as “Mediterranean green-greenhouse produce”) that emphasizes the link between its intrinsic high-quality properties, the origin of that specific product and the sustainability of its production process.
Keywords: energy, environmental impact, greenhouse, soilless, water use efficiency