Development of Climate Change Adaptation Strategies for Rice-wheat Cropping System of Punjab Pakistan

Climate change is an established fact and its impacts on water, agriculture, health, biodiversity, forest and socio-economic sectors are quite visible around the globe. By virtue of its geographical location, Pakistan is highly vulnerable to the consequent climate change because of global warming. Adaptation to climate change and building resilience among ecosystems and people to respond to climate variability and hazard threats are relatively new concepts. Rice-wheat cropping system zone is the bread basket of Punjab, Pakistan and comprising more than 1 million farm families. There is an urgent need for improved climate modeling and forecasting that can provide a basis for informed decision-making and the implementation of adaptation strategies. For this study crop growth models (DSSAT and APSIM) were calibrated and evaluated on experimental field data to develop the robust genetic coefficients. Models were validated using farmers’ field data. Survey data for rice and wheat in Rice-wheat cropping zone of Punjab were collected for this study. An extensive farm survey for 155 farms from the selected five districts Sheikhupura, Nankana Sahib, HafizAbad, Gujranwala, and Sialkot was conducted. Surveyed data (initial condition, crop management, soil characteristic) were used to create the input files in both DSSAT and APSIM. The past climate of the study region, baseline (1981–2010) was analyzed by using the available weather station data and future climate projection were generated by General Circulation Models (GCMs) for mid-century (2040-2069) under RCP 8.5. Five GCMs (CCSM4, GFDLESM2M, HadGEM2-ES, MIROC5, and MPI-ESM-MR) were used for the generation of climate projections. Trade of Analysis model for Multidimensional (TOA-MD) was used for economic analysis. Results of climate change scenarios showed that there would be mean 2.8 °C rise in maximum and 2.2 31 °C in minimum temperature for mid-century (2040-2069) in Rice-wheat (RW) cropping system of Punjab, Pakistan. In Rice average yield reduction in DSSAT and APSIM was 15.2% and 17.2% while in Wheat average yield reduction by DSSAT and APSIM was 14.1% and 12% during mid-century (2040-2069). A close agreement was observed between farmer and simulated fine rice yield with good statistical indices such as Root Mean Square Error (RMSE) 409 kg ha-1 and 440 kg ha-1 with d-index (0.80 and 0.78) for DSSAT and APSIM models, respectively. Economic loss of 83% farm household, if they continue to use current production technology in changed climate. Adaptation strategies using Representative Concentration Pathways (RAP’s) were developed to achieve high productivity and meet the need of growing population, it would be required to increase the planting density, fertilizer use and reduce the irrigation amount up to 15% over current with greater potential for promising cultivars. This suggested that due to projected rise in temperature, the cropping seasons will be affected and 5 days earlier transplanting of rice nursery and two weeks earlier in wheat planting over current would be recommended. These strategies have a significant impact in reducing the vulnerabilities of the changing climate with 33% improvement in rice yield to sustain production in Rice-wheat cropping system. Significant reduction in poverty (5-6%) among farm households, if adaptation takes place in this zone