Modeling Responses of Fine Rice Growth and Yield to Increased Carbon Dioxide Concentration, Temperature and Precipitation under Current Future Climate Scenarios

摘要

Irrigated rice production is a major food source for a large portion of the world’s population. Potential impacts of global climate change (elevated carbon dioxide (CO2) and/or elevated temperature) on rice productivity can be predicted with simulation models. The CERES-Rice model (V-4.0.2) was calibrated and validated for transplanted fine rice using the soil and weather parameters of three locations (Faisalabad, Kala Shah Kaku, Gujranwala) in the Punjab –Pakistan. Decision Support System for Agro-technology transfer (DSSAT) model’s component Weatherman was used to generate future weather scenarios based on weather data from the experimental sites. These weather scenarios were used in the Seasonal Analysis programme to simulate the impacts of changing weather variables on rice growth and yield. On an average with the elevation of CO2 upto 550 ppm, paddy yield increased by 1.53% to 4.48% at different locations. Model simulations showed that increasing temperature shortened crop duration by 4-5 days at Kala Shah Kaku and Gujranwala sites, respectively. Consequently, paddy yield was decreased at all locations, with increase in temperature. Seasonal Analysis programme predicted that transplanting of fine rice in the fourth week of July will be the most efficient transplanting date in future climate at all the three sites. Results of economic strategy analysis, specifically the Mean- Gini Dominance analysis, could be better strategy to increase the efficiency of rice cropping system under variable environment. The present study revealed that the generated future weather data were reliable and DSSAT could successfully use it to predict the future rice yield under different management practices and select the best one for sustainable rice production.