Reducing food waste and changing cropping patterns to reduce water consumption and pollution in cereal production in Iran

Abstract Availability of sufficient and clean freshwater has become a growing constraint to sustainable agricultural development in many countries. We explore two pathways that hold the potential to reduce water consumption and pollution related to cereal production in Iran: reducing food waste and changing cropping patterns. Hereto, we first evaluated the green, blue and grey water footprint (WF) associated with production of wheat, barley and rice. Next, we assessed resulting water scarcity and pollution levels at the provincial scale, for the period 1980-2010. Both total WF and its blue water share were found to have increased considerably from 1980 on. For the year 2010 (a representative hydrological year), results show that the national total green-blue WF of production of these major cereals is 43×109 m3. Regarding the grey WF of production, 30×109 m3 was required to take up surplus N loads to water bodies. Resulting blue water scarcity and water pollution levels are highest in the arid and semi-arid provinces, caused in part by cereal production destined for export to other regions. Exploring reduction pathways showed that bridling cereal waste allows a potential reduction in both the green-blue WF and grey WF of production of up to 5% each. Relocating production areas and modifying cereal trade patterns from water-abundant to scarcer provinces could save up to 3.5% in the green-blue WF of production and up to 25% in the grey WF.