From field to table through the long way. Analyzing the global supply chain of Spanish tomato

Modern food chains are energy intensive processes, which implies environmental impacts and a dependence on non-renewable resources. Nevertheless, some studies tend to underestimate the energy use of transport by assuming some simplifications in their models or by not considering aggregate levels of analysis. Tomatoes are a key agricultural commodity, and Spain is the second largest tomato producer and exporter in Europe. This paper comparatively analyses the embodied energy associated with consumption products of the tomato food chain in Spain including the products consumed in the country and those exported to third countries, taking into account energy consumption from production to household distribution.

We estimate the fluxes of raw materials and products of the whole chain combining official databases and business reports to reconstruct the location and interconnection between international, national and provincial nodes of production, processing and consumption. On the one hand, agrarian specialization concentrates production in provinces with greenhouse off-season production, which contributes significantly to the overall energy requirement. In addition, manufactured products have a high level of embodied energy, particularly in Spain's product consumption mix, which is the key factor in the chain, both in exports and in national food consumption. On the other hand, provincial productive and export specialization determines the existence of decoupling between agricultural, manufacturing and exporting clusters throughout the chain, significantly increasing energy use per unit consumed or exported by implying recirculation transport flows between provinces, which is particularly evident in exporting provinces supplying European countries. This process is neglected in previous LCA studies, leading to an underestimation of the energy cost.

As a general conclusion, recirculation due to geographical specialization of different stages of the food chain has been shown to be a major contributor to energy use in the Spanish tomato chain and should be further studied in food chains of other products and countries. Additionally, approaches to lower food system energy use should not only focus on specific measures on separated phases of the food chain, but on reconfiguring its territorial organization and its modes of production and processing.