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.

中文翻译：

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减少食物浪费和改变种植模式，以减少伊朗谷物生产中的用水量和污染

摘要 充足和清洁淡水的供应已成为许多国家可持续农业发展的日益制约因素。我们探索了两种可能减少与伊朗谷物生产相关的水资源消耗和污染的途径：减少食物浪费和改变种植模式。为此，我们首先评估了与小麦、大麦和水稻生产相关的绿色、蓝色和灰色水足迹 (WF)。接下来，我们评估了 1980 年至 2010 年期间全省范围内的水资源短缺和污染水平。发现自 1980 年以来，总 WF 及其蓝水份额均显着增加。2010 年（代表性水文年），结果显示，全国这些主要谷物生产的绿蓝 WF 总量为 43 × 109 m3。对于生产的灰色 WF，需要 30 × 109 m3 来吸收水体中多余的 N 负荷。干旱和半干旱省份造成的蓝水短缺和水污染程度最高，部分原因是谷物生产出口到其他地区。探索减少途径表明，控制谷物废物可使绿-蓝 WF 和灰色 WF 的产量分别减少 5%。将生产区搬迁并改变谷物贸易模式，从水资源丰富的省份到水资源匮乏的省份，绿色-蓝色 WF 生产最多可节省 3.5%，灰色 WF 最多可节省 25%。部分原因是谷物生产出口到其他地区。探索减少途径表明，控制谷物废物可使绿-蓝 WF 和灰色 WF 的产量分别减少 5%。将生产区搬迁并改变谷物贸易模式，从水资源丰富的省份到水资源匮乏的省份，绿色-蓝色 WF 生产最多可节省 3.5%，灰色 WF 最多可节省 25%。部分原因是谷物生产出口到其他地区。探索减少途径表明，控制谷物废物可使绿-蓝 WF 和灰色 WF 的产量分别减少 5%。将生产区搬迁并改变谷物贸易模式，从水资源丰富的省份到水资源匮乏的省份，绿色-蓝色 WF 生产最多可节省 3.5%，灰色 WF 最多可节省 25%。