Irrigated corn and non-irrigated wheat carbon and water footprints in northeast Spain

Abstract

Irrigation improves yields and enables the production of many crops in areas where it would otherwise be difficult owing to a lack of rainfall. Irrigation, on the other hand, may have a number of negative environmental consequences, which must be well understood before mitigation measures can be implemented. The life cycle assessment methodology was used to compare the main irrigated and no irrigated crops in Northeast Spain (corn and wheat, respectively), identifying the processes that have the greatest impact on environmental impacts (carbon and water footprint categories), and providing scientifically sound information to aid government decisions. Because of worries about climate change and water shortage, the IPCC 2013 GWP (carbon footprint) and the water scarcity indicator were chosen as the methodologies for assessing environmental effects (water footprint). The study region, a 7.38-km2 basin, was observed for 12 years, including before, during, and after irrigation was implemented. The cultivation of 1 ha over the course of a year was the functional unit with which all material and energy flows were linked. Irrigated corn has a greater total carbon footprint, however when factoring the increased productivity obtained with irrigation, the emissions per kilogram of maize drop, favoring this irrigated crop. When it came to the water footprint, the amounts of irrigation water used were so large that production could not compensate for the negative effects of water consumption in corn. Considering productivities and gross revenues, however, puts the findings closer together. The major contributions to the negative effects discovered were fertilizer usage (carbon footprint) and irrigation water (water footprint).