Forecasting climate change impacts and evaluation of adaptation options for maize cropping in the hilly terrain of Himalayas: Sikkim, India

Abstract

An investigation was carried out to assess the climate change impacts on rainfed maize yield using AquaCrop and CERES–maize crop simulation models, and evaluation of adaptation measures were performed for Sikkim state of India. Data related to crop phenology retrieved from the field experiments were used to calibrate and validate the crop models for three representative sites. Climate projections of six global circulation models (ECHAM5, CCSM, HadCM3, CSIRO-MK3.0, CGCM3.1, and MIROC3.2) for scenarios A2 and B2 were bias-corrected at station scale by power law transformation. Simulation results by the two crop models indicate a significant declination in the yield of NLD-White variety of maize ranging from 4.7 ± 1.4 to 20.4 ± 7.2 % for the future time windows under A2 scenario and 2.5 ± 0.9 to 15.8 ± 5.7 % under B2 scenario relative to the yield simulated for the baseline period of 1991–2000. It is also observed that, for a particular temperature, yield remarkably increases with escalated carbon dioxide (CO2) concentration. On contrary, increase in temperature reduces the yield at a particular CO2 concentration. The overall decline in the yield under future climate scenarios can be alleviated by early planting, appropriate nutrient management, introducing supplementary irrigation, and shifting to heat-tolerant varieties.