Energy, water and fertilizer requirement of a closed loop soilless culture of greenhouse cherry tomato in Sicily

The South-east cost of Sicily, with more of 5.000 ha of protected crops, is one of the most important area in the Mediterranean horticulture, but the incoming prohibition of methyl bromide and the progressive salinisation of irrigation water could limit the future expansion of this economical sector. Soilless cultures may be a tool to save water, fertiliser and labour, but nowadays they are employed in less than 1% of total greenhouse area. The paper reports the results of a demonstration project (ProBio) conducted in the province of Ragusa to promote the use of closed-loop soilless culture for cherry tomato, that is the most typical vegetable crop in Sicily. A simple soilless system was set up with slow sand filtration of the recycling solution and its performance in terms of water, electric energy and fertilizer consumption was recorded together with fruit yield and quality.