A preliminary assessment of water footprint components in a Mediterranean olive grove

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 (m3 t-1) was calculated as the amount of the annual water consumption (m3) per unit of yield (t). Classical components green, blue, grey (WFBlue, WFGreen and WFGray, respectively) of the water footprint were determined 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.