671 A Preliminary Assessment of Water Footprint Components in a Mediterranean Olive Grove B. Dichio, A.M. Palese, G. Montanaro and E. Xylogiannis DiCEM Università degli Studi della Basilicata Potenza Italy A. Sofo Scuola di Scienze Agrarie, Forestali, Alimentari ed Ambientali Università degli Studi della Basilicata Potenza Italy Keywords: water management; water scarcity; water use efficiency; virtual water Abstract The water footprint is an indicator of the consumers’ (or producers’) water consumption. It can be a useful tool to plan appropriate water management strategies within a territory. This 4-year (2005-2008) study provides an assessment of the water footprint of an irrigated (I) olive orchard against a rainfed (non-irrigated, NI) one. Olive trees were grown under semi-arid conditions. The irrigated field received treated urban wastewater and was managed according to sustainable techniques (i.e. cover crops, recycle of pruning material). In the NI grove, soil was tilled and pruning residues were removed. In each year, the water footprint (m 3 t -1 ) was calculated as the amount of the annual water consumption (m 3 ) per unit of yield (t). Classical components green, blue, grey (WFBlue, WFGreen and WFGray, respectively) of the water footprint were deter- mined and the total (WFTot) was calculated as their summation. On average, total water footprint of the NI block was  45% of that of I block. The WFGreen was the most important component in both irrigated and non-irrigated grove, accounting for the 48 and 90% of the WFTot, respectively. INTRODUCTION Water is a resource long wasted, growing expensive, and soon is going to be a really rare good. Aquifers are falling, glaciers vanishing, reservoirs drying up day by day and rivers no longer owing to the sea. Climate change makes these problems worse. As the world population is increasing, the demand for water increases. World population was 2.5 billion in ’50s and would reach 9 billion in 2050 year (United Nations, 2009). Hence, annual water demands for horticultural crop production are expected to increase from approximately 7 million cubic meters to approximately 14 million cubic meters in 2055 (Rosegrant et al., 2007). The proportion of people living in countries chronically short of water, which stood at 8% at the turn of 21 st century, is set to rise at 45% (4 billion) in 2050 (http:// www.economist.com/node/16136302). People in temperate climates, where the rain falls moderately all the year long, may not realize how much water is needed for farming. In Britain, for example, farming takes only 3% of all water withdrawals. In the United States, by contrast, 41% is used by agriculture, almost all of it for irrigation. In China, farming takes almost 70%, and in India nearly 90% of the available water. For the world as a whole, agriculture accounts for almost 70% (http://www.economist.com/node/ 16136302). To prevent all these bleak forecasts a lot of governments, organizations and researchers are trying to find out ways to reduce the water consumption at a world, national, regional and local level without a significant impact on the production. The water footprint is part of a larger family of footprint concepts that has been developed in the environmental sciences over the past decades. The concept of water footprint has been introduced in 2002 by Hoekstra and Hung (2002) in analogy to the carbon and ecological footprint. It is a consumptive-based indicator of fresh water use of a consumer or Proc. VII th IS on Irrigation of Horticultural Crops Eds.: P. Braun et al. Acta Hort. 1038, ISHS 2014