Response of the water footprint of maize production to high temperatures in the Huang-Huai-Hai region of China

BACKGROUND Water footprint (WF) can comprehensively evaluate agricultural water use efficiency under high-temperature weather. Based on the historical meteorological data in the Huang-Huai-Hai (3H) region of China, this study used the percentile threshold method to analyze the distribution of high-temperature events and set three types of meteorological scenarios, namely the actual temperature scenario (S1), the high temperatures in the ear stage scenario (S2), and the high temperatures in the flowering-maturity stage scenario (S3). The growing degree day (GDD) mode and calendar day (CD) mode in the AquaCrop model were used to simulate the yield per unit area (Y-unit) of maize under different temperature scenarios and then the crop evapotranspiration (ETc) and production WF during maize growth period were calculated. RESULTS The occurrence frequency of extreme high-temperature event in ear stage in the 3H region was lower than that in the flowering-maturity stage. There were significant differences in the WF of maize between S1 and S2 and between S1 and S3 in GDD mode, and significant differences in Y-unit, ETc, and WF of maize under three temperature scenarios in the CD mode. CONCLUSION High temperature events occur in maize growth period, especially in the flowering-maturity stage, will increase the WF of maize. Measures such as changing the planting structure, changing the sowing date of maize and cultivating heat-resistant maize varieties could be taken to reduce the negative impacts of high-temperature weather. (c) 2022 Society of Chemical Industry.

Automated summary

The occurrence of high-temperature events during the maize growth period, especially in the flowering-maturity stage, will increase the water footprint of maize. Measures such as changing planting structures, adjusting maize sowing dates, and cultivating heat-resistant maize varieties can be taken to mitigate the negative impacts of high-temperature weather.