Simulating the impact of climate change and its variability on growth and yield of crops Kalra Naveen1, Suneja Poonam2, Mendiratta Nisha3, Gupta Navindu4 1Principal Scientist, Tata Chemicals Limited, Aligarh, Uttar Pradesh, India. Email id: drnkalra@gmail.com 2Ex-Meteorologist Grade II, Indian Meteorological Department, New Delhi, India 3Climate Change Programme, Department of Science and Technology, New Delhi, India 4Senior Scientist, Environmental Sciences Division, Indian Agricultural Research Institute, New Delhi, India Abstract There is a need to delineate vulnerable regions and identify suitable adaptation and mitigation strategies to sustain agricultural productivity under global climate change and frequently occurring extreme climatic events. Agricultural productivity can be affected by climate change, directly, due to changes in temperature, precipitation or CO2 levels, and indirectly, through changes in soil health (physical, chemical and biological), distribution and frequency of infestation by insects/pests. Field/control chamber-based multidisciplinary research results, covering soil –water –plant –insects –pests and atmospheric continuum processes, were used to develop dynamic/mechanistic crop growth models. These models, after thorough validation (namely WTGROWS, INFOCROP and DSSAT), have been successfully used for evaluating soil and crop processes in relation to climate change. Using these models, differential response of reduced crop yields to rising temperatures was noticed at locations. Interaction of delta change in CO2 and temperature was significant, as noticed through growth and yield response of crops. Simulation using the WTGROWS model indicated that optimal sowing date in wheat advanced by 5 –8 days per degree rise in temperature (adaptation strategy). The impact in crops was more pronounced in relatively warmer regions, which became highly adverse under limited supply of water and nutrients. Shifts in the productivity centres northward for major crops, in relation to temperature rise and enhanced CO2 concentration, were noticed. Using WTGROWS and DSSAT, the impact of aerosol was evaluated on rice, wheat and sugarcane, and radiation reduction was compensated with the enhancement in duration of the crops due to cooling and marginal reduction in yield of crops was noticed. The crop –pest –weather interaction and socioeconomic components in the climate change impact evaluation are relatively weaker in the present models. In INFOCROP, insect –pest subroutine has been addressed and successfully used for climate change studies. There is a need to develop simulation models/life-cycle assessment methodology by integrating the multiwater/nutrients interaction for realistic estimate of growth and yield of crops, in designing appropriate nutrient management strategies, in evaluating the environmental impacts and also in developing green crop nutrition products. Most of the climate change studies in the past are point based, extrapolated empirically for assessing the regional impacts of climate change. There is a need to evolve methodology for integrating relational layers of biophysical and socioeconomic inputs, along with climate change scenarios and crop simulation tools for region wise estimates of the impacts on agriculture, including vulnerability, mitigation and adaptation strategies. Top Keywords Simulation, Climate change and its variability, INFOCROP, Adaptation, Mitigation. Top |