Balancing water use and nutrition for crop production in a highly dense population – Bangladesh

【背景・経緯】
The challenge of sustainably feeding billions, especially in densely populated economies like Bangladesh, demands addressing crop production’s environmental impacts, notably sustainable water use. Nutrient adequacy refers to the provision of sufficient essential nutrients—such as vitamins and minerals—to meet the dietary needs of a population. Our study revealed Bangladesh overused 20 billion m³ of freshwater (19% of total consumption) for crops, particularly rice. This context sets the stage for exploring how shifts in crop consumption can potentially enhance both nutritional adequacy and sustainable water use.

 

【成果】
Fig. 1 shows the relationship between the nutrient adequacy of consumed crops in Bangladesh and freshwater overconsumption. A few crops dominate freshwater overconsumption, notably rice, due to its massive consumption. To promote sustainability, it is advisable to favor crops that offer higher nutrient adequacy and minimize freshwater use. Vegetables and fruits, while consumed less, induce less freshwater overconsumption. The nutrient adequacy compared with overconsumption for vegetables is higher than for fruits and grains. Shifting consumption patterns to sustainable crops like cauliflowers, broccoli, cabbage, lettuce, and spinach is key. Substituting crops within the same category with higher nutrient adequacy but lower water use should be considered, e.g., wheat instead of rice. Potatoes, sweet potatoes, and maize can significantly reduce water overconsumption and improve nutrient adequacy. Encouraging increased consumption of these efficient crops over rice presents an option for achieving balanced nutrition and sustainable water use.

 

Figure 1. Freshwater overconsumption and nutrient adequacy in Bangladesh. Both axes are log-transformed; bubble size represents total crop consumption.

 

【成果の意義・今後の展開】

Shifting crop consumption from rice to alternative crops, such as potatoes, sweet potatoes, and maize, can improve both nutritional adequacy and sustainable water use. Furthermore, shifting production to areas with less pressure and promoting fruits and vegetables can aid sustainable water management and align with healthy lifestyles. Moving forward, our research is expanding to assess the global water use impact of adopting a planetary diet, aligning with international agendas focused on biodiversity conservation.

 

 

※ Islam, K., Yokoi, R., Pastor, A.V., and Motoshita, M. (2023). Balancing water use and nutrition for crop production in a highly dense population – Bangladesh. Sustainable Production and Consumption Volume 43, December 2023, Pages 389-399, https://doi.org/10.1016/j.spc.2023.11.020

2024年07月17日