Water, Energy, Food and Environment Nexus in Six Irrigation Districts from the Spanish Duero Basin

Abstract

Background and Objective: Irrigated agriculture is a key factor to foster crop production and the agribusiness sector. It also contributes to develop rural areas and maintain the population in Spanish rural villages. However, water resources are not always available to fulfill crop water requirements when needed. In addition, the Spanish Plan for modernization of hydraulic irrigation infrastructures (2000) has increased energy consumption and drastically has raised the energy cost in the last five years. Natural environment in irrigated areas has modified and the application of agrochemicals and pesticides, together with aquifer’s over exploitation, have degraded groundwater quality and have extinct river fishes. In the one hand, the European, National and Regional Normative on ecosystems requirements and services, must be met. On the other hand, farmers want to stay in the rural areas as long as their gross income be higher than the farming’ expenses. Likewise, climate change predictions in semi and arid areas foresee an increase in temperature, which will increase crop water needs, and droughts’ increase. Duero is the second largest Spanish river which supplies water to a larger and depopulated area where agriculture is the major economic sector. The irrigated area has doubled in the last fifteen years and irrigation consumes 85% of total water resources at present. Perspectives for the near future highlight the need to foster rural development and settle population. The challenge ahead is to maintain irrigation but tackling the issues on water scarcity, energy prices and fertilizer cost. This work is aimed at providing some clues on the water-energy-food-ecosystem nexus in rural areas of the Duero basin.
 Methodology: Six Duero irrigation districts (ID) (Adaja, Tordesillas, Aranda-Tordesillas, Tordesillas-Zamora, Villalar de los Comuneros and Carracillo) have been selected and the study focuses on the evolution of water and energy consumption, as well as the main crops production, the ecosystems’ status and the major municipalities population trends across the IDs, from 2010 to 2020.
 Results and Conclusion: The annual average water supply was different among IDs; the highest value corresponded to “Tordesillas” (6895 m3/ha) and “Adaja” (6287 m3/ha). The energy consumption was very high in all IDs. Likewise, the highest water productivity and total gross income indices corresponded to potato and sugar beet and the lowest to barley and sunflower. The total production costs in the last two crops were higher than the gross income and consequently, it would result in economic losses in the case of subsidies lack. The population in the main municipalities of the six IDs has decreased in the study period and does not meet the goal of the Spanish Plan for modernizing irrigation systems of maintaining/increasing population in rural areas. The results would be a valuable tool to develop sustainable solutions (at regional scale) for fair and sustainable sharing food production resources that will affect the water, energy, food and ecosystem (WEFE) nexus.