28/11/2013 Organic in greenhouses Francesco Ceglie - Italy The main objectives of the experimentation are: to compare yields and to evaluate the organic farming systems either from an agronomic and an environmental point of view. Organic farming has to tackle with the huge global challenges due to climate change, water shortages, food security and safety, environmental pollution, biodiversity loss and non-renewable resources depletion. Under these exceptional and stressing conditions it has been proven that high input agricultural systems both conventional and organic are not resilient. Continuous monoculture, nutrient losses, water and energy consumption, greenhouse gas emissions and use of soluble organic fertilizers should be minimized to obtain a sustainable production in organic greenhouse horticulture (OGH) . Crop rotations including cover crops are not common in organic greenhouse, due to the high cost of investment and specialization.The choice of crop grown in any season is largely influenced by market forces in OGH and farmers, to maximize profits, are pushed to repeatedly grow the same crop on the same land. So, OGH farmers are induced to intensify their production systems and follow market demand more than sustainability principles. At European Union level the debate is intense and a review of organic protected cropping standards and regulations is taking place. A long-term experiment was established at the Mediterranean Agronomic Institute of Bari (MAIB) to compare different systems of organic vegetable production in the course of a crop rotation under unheated tunnel. It is expected to develop practicable agroecological managements and cropping system designs that can be easily adopted by organic greenhouse growers to reduce the dependency on external inputs of production thereby lowering environmental pollution and enhancing system sustainability.