Applications of CERES-Rice and CERES-Wheat in Research, Policy and Climate Change Studies in Asia: A Review

摘要

Crop models have many current and potential uses for improving research understanding, crop management decisions, policy planning and implementations and adapting to current and future climate change . A comprehensive literature review was done to synthesize and assess the various applications of CERES-Rice and CERES-Wheat in Asia, with a view to apply the `essons learnt` to make the research and development more effective. Examples are given of the use of CERES-Rice and CERES-Wheat for yield gap and yield trend analyses, for improving overall crop management by making appropriate planting decisions, devising improved cultural practices and developing improved nitrogen, water and pest management strategies. In policy, the models are used to predict the impacts of climate change on crop productivity and to assist government in the strategic decision making and planning. Among all, predicting the impacts of various climate change scenarios on crop yield and water use and identifying adaptive strategies to the changed climate is the most important area of application dominating the literature. Most climate change studies revealed that increased temperatures decreased growth duration and yield and water use of both crops, but with more adverse effect on wheat. Increased CO2 concentrations increased yield of both crops, but the positive effects of CO2 could be offset by negative effects of increased temperatures and vice versa. Increased rainfall increased evapo-transpiration of rice and increased yield, especially in rainfed areas. Adverse climate change would result in larger decreases in yield in low- and smaller decreases in mid- to high-latitudes, but the severity of blast disease would be high in cool sub-tropical and temperate and low in warm humid tropical areas. Some of the biggest impacts of climate change would be reduced wheat yields in Pakistan and northwest India and reduced rice yields in Bangladesh and Thailand. Effects of climate change in China and Japan were variable depending on latitude. Early planting, irrigation and selection and breeding cultivars for adaptation to climate change were some of the adaptive strategies for both crops. The literature reveals that despite a great deal of current use of these models by the scientific community, frustratingly, there is neither any evidence in the use or uptake of the outputs of these models by farmers, governments, or other clients and stakeholders, nor in the development or adoption of revised management guidelines in Asia. Further, studies on the impacts and adaptation of climate change revealed that there is very little evidence that the model results have really been used by any stakeholders or policy makers in the state or national levels in the countries of Asia. One of the major limitations for the scientific community is unavailability of quality input data on weather, soil and crop management for model evaluation. Nevertheless, we believe that the use of CERES will play an increasingly important role in improving research understanding and decision making in crop management, in assisting policy and in preparing and adapting to the current and future climate change . Hence, while recognizing the potential limitations, we suggest that efforts be continued to facilitate the uptake of the model results by farmers, stakeholders and the policy makers if CERES rice and wheat have to make contributions in the real world.