Impact Assessment of Climate Change on Rain-fed Lowland Rice Productivity in Lao PDR and Farmers’ Adaptation Preference

Abstract

기후변화는 국내외적으로 중요하게 다루어지는 농업환경 이슈 중 하나이다. 연구는 APEC 기후센터와 본 연구원 농업환경 연구팀이 함께 작업한 내용으로, 라오스 지역 천수답 쌀 농가에서의 적응 기술 적용에 대한 생산량 변화와 각 적응 기술에 대한 농업인의 지불의사액을 분석한 내용이다.

Rice (Oryza sativa L.) is one of the most important crops in the context of food security and economy in Lao PDR. We attempted to provide adequate adaptation strategies to cope with climate change by the assessment of the climate change impacts on rice productivity in wet season lowland rice production systems in Lao PDR through the CERES-Rice model for the two rice cultivars (TDK8 and TDK11) and to evaluate adaptation preference of the rice farmers in the country through a climate change adaptation survey approach. The two rice cultivars (TDK8 and TDK11) were selected for the rice productivity simulations under climate change in Vientiane Capital (Lao PDR). The National Aeronautics and Space Administration Prediction Of Worldwide Energy Resource (NASA POWER) meteorological variables and Coordinated Regional Climate Downscaling Experiment (CORDEX) climate variables were collected for the inputs of the CERES-Rice model. A total of eight adaptions including no adaptation from irrigation, nitrogen application rates, and transplanting date shifting were simulated by the CERES-Rice model. The simulation results showed that the highest increase (14.1%) in rice yield was simulated in the 2040s under the RCP 4.5 scenario with the nitrogen fertilizer application rate of 180kg-N ha-1 (i.e. three times as much as the recommended application rate), while a decrease (-26.5%) in rice yield was highest in the 2080s under the RCP 8.5 scenario with the +20 days shifting transplanting date. These findings indicate that nitrogen fertilizer application rates can be an efficacious adaptation to offset the negative impacts of climate change. The study also revealed that the transplanting date shifting may not be a sufficient adaption for this region to cope with climate change. These adaptations were evaluated from a climate change adaptation survey to investigate rice farmers’ preference in Vientiane Capital. The results from the survey showed that the farmers prefer installing the auto irrigation system and applying nitrogen fertilizer doubled (180kg-N ha-1) to applying nitrogen fertilizer tripled and shifting transplanting date. Specifically, the farming experience of household head (years), yearly machine rental cost (thousand kip 10a-1), yearly harvest cost (thousand kip 10a-1), whether they think climate change has affected/would affect rice production negatively (no=0, yes=1) are statistically significant variables to determine whether the farmers would install the auto irrigation system. With regard to nitrogen fertilizer application doubled, yearly harvest cost (thousand kip 10a-1) and yearly household labor used (hours) are statistically significant for the farmers to decide whether to apply the nitrogen fertilizer doubled. Among those variables, the farming experience of household head and opinion about climate change impact, and the yearly harvest cost and household labor used are significant variables to determine the willingness to pay for installing the auto irrigation system and applying the nitrogen fertilizer doubled. It is concluded that this study can be useful to enhance food security of Lao PDR by providing efficacious agricultural managements to reduce the negative impacts of climate change on rice productivity.