Adaptation strategies for rice cultivation under climate change in Central Vietnam

This study investigates the impact of climate change on winter and summer rice (Oryza sativa) yield and evaluates several adaptation measures to overcome the negative impact of climate change on rice production in the Quang Nam province of Vietnam. Future climate change scenarios for time periods in the 2020s, 2050s and 2080s were projected by downscaling the outputs of the General Circulation Model (GCM), Hadley Centre Coupled Model, version 3 (HadCM3) A2 and B2 scenarios. The AquaCrop model was used to simulate the impact of future climates on rice yield. The minimum and maximum temperature of the province is projected to increase by 0.35-1.72 A degrees C and 0.93-3.69 A degrees C respectively in future. Similarly, the annual precipitation is expected to increase by 9.75 % in the 2080s. Results show that climate change will reduce rice yield from 1.29 to 23.05 % during the winter season for both scenarios and all time periods, whereas an increase in yield by 2.07 to 6.66 % is expected in the summer season for the 2020s and 2050s; relative to baseline yield. The overall decrease of rice yield in the winter season can be offset, and rice yield in the summer season can be enhanced to potential levels by altering the transplanting dates and by introducing supplementary irrigation. Late transplanting of rice shows an increase of yield by 20-27 % in future. Whereas supplementary irrigation of rice in the winter season shows an increase in yield of up to 42 % in future. Increasing the fertilizer application rate enhances the yield from 0.3 to 29.8 % under future climates. Similarly, changing the number of doses of fertilizer application increased rice yield by 1.8 to 5.1 %, relative to the current practice of single dose application. Shifting to other heat tolerant varieties also increased the rice production. Based on the findings, changing planting dates, supplementary irrigation, proper nutrient management and adopting to new rice cultivars can be beneficial for the adaptation of rice cultivation under climate change scenarios in central Vietnam.