The water footprint and virtual water exports of Spanish tomatoes

D. CHICO et al. 25FIGURE 7. Average green, blue and grey water footprint (WF) of openair (rainfed and irrigated) and greenhouse production (l/kg)Source: Own elaboration.icantly even within the same province. Moreover, tomatoand in general horticultural crops may be grown within awide range of production systems in mild climates. In theSpanish case, this whole range is covered, with production(albeit small) of rainfed tomato, low intensity traditionaltomato, highly productive intensive open-air tomato and themost intensive, even technology-driven greenhouse production(Maroto, 2002; Nuez, 1995).As already mentioned, there are sharp differences in thewater footprint across production systems. Rainfed tomatoproduction has by far the highest water footprint with 966l/kg. The grey water footprints of open-air irrigated andgreenhouse production systems are small in comparison toit, partly due to their much higher yields. The Nitrogen bal-