The water footprint and virtual water exports of Spanish tomatoes

D. CHICO et al. 41different productions. While the provinces irrigated with surfacewater produce mainly tomatoes intended for the industryin open-air systems, those accounted for as irrigated withgroundwater produce fresh tomato for export, more valuable.Virtual water exports related to tomato exports representabout 2.5% of total Spanish water exports, without consideringgrey water (Garrido et al., 2010). However, in economicterms (€/m 3 ) tomato exports are 350% larger than the averageexports (Garrido et al., 2010), with 8.81 €/m 3 comparedwith the average 2.5 €/m 3 of the average exports. Reducingthe blue and green water footprint of tomato production willnot be easy because of plant physiology restrictions, but thegrey water component can be significantly reduced. Shouldthis be achieved by optimizing the timing and technique ofNitrogen applications, so that less is needed and/or lessleaches or runs off, Spanish tomato exports’s sustainabilitywould significantly improve. Water footprint evaluationsthat omit the grey component would lead to incomplete conclusions,as they may lead to increase efficiency in direct waterconsumption but fail to take into account the environmentalpressure related to pollution.Finally, the water footprint contextualized in space andtime can provide useful information for benchmarking, indentifyingbest practices and achieving a more integratedwater resource management. However, to obtain a comprehensivepicture, not only the (eco) efficiency in terms ofm 3 /ton should be considered, but also the context-specific totalcumulative water footprint.7. ACKNOWLEDGEMENTSWe would like to thank Professor A. Saa, J. M.ª Duránand C. Hernández of the Technical University of Madrid for