Modelling climate change impacts on wet and dry season rice in Cambodia

Irregular rainfall, rising temperatures and changing frequency intensity of extreme weather events are projected to reduce crop yields threaten food security across the tropical monsoon sub-region. However, anticipated extent impact on water productivity (CWP) is not yet thoroughly understood. The impacts climate change rice CWP assessed over Northern Tonle Sap Basin in Cambodia by applying AquaCrop model into mid- (2041–2070) long- (2071–2099) future under two Representative Concentration Pathways (RCPs) (4.5 8.5). Short (95 days), medium (125 days) long (155 cycle varieties tested during wet dry seasons. An assessment different sowing dates irrigation strategies (fixed net season) elucidated variation response environmental conditions. Higher (+15% 2041–2070 +30% 2071–2099) values (+42% expected if using short-cycle varieties, particular when sown July. Dry season also increase (+28% higher simulated a greenhouse gas emission scenario (RCP 8.5) compared with 4.5) as result CO2 fertilization effect. Depending climatic scenario, variety, scheme, date, increasing heat drought-stress conditions likely have time. Overall, this study highlights benefits adjusting calendars identify most suitable schedules variety effectively adapt climate.