Water footprint analysis of wheat production

Water footprint (WF) is an indicator of the volume of freshwater resource consumption that incorporates direct and indirect water use. Global freshwater resources are prone to detriment due to water consumption in agriculture. Wheat production contributes considerably to the global water consumption burden. A life cycle assessment-based WF analysis of wheat production was conducted to quantify the water consumption during the entire life cycle of wheat systematically and scientifically. We quantified the temporal distribution of WF of wheat production in Shandong Province, China, from 2009 to 2015 and analyzed the spatial distribution of direct WF of wheat production in 2015. Soil testing and an on-site survey were conducted to examine fertilization overuse. Results showed that gray WF accounted for the largest proportion (nearly 46%), followed by green and blue WFs. Gray WF was mainly from aquatic eutrophication (over 96%), and its key substances were chemical oxygen demand and total phosphorus. Direct water consumption, direct emissions, fertilizer use, and diesel consumption exhibited high potential impacts. This study indicated that rational fertilization on the basis of the soil testing, improving the diesel consumption efficiency, and wheat straw returning to fields have great potential for intensifying water resource management.