Impact of climate change scenarios on yield, water and nitrogen-balance and -use efficiency of rice–wheat cropping system

The study focuses on (i) obtaining PRECIS climate change scenario (A1B) data for Ludhiana location and minimizing its bias, (ii) simulation of its impact on crop yield, crop duration, water and nitrogen-balance and -use efficiency of rice–wheat cropping system with CropSyst model and (iii) mitigation of climate change impact by shifting trans-/planting dates of the crops. Model simulations predict reduction in crop yields in future associated with shortening of growth period due to increased temperature. Yield reduction was more with increase in maximum temperature than minimum; and in finer- than coarser-textured soil. Increased rainfall in future would decrease irrigation water requirement of crops but would not offset the adverse effect of increased temperature. Although evapotranspiration and nitrogen uptake would decrease in the end century, yet relatively more decrease in yield would lower water use and nitrogen use efficiency. Shifting trans-/planting dates of rice and wheat to 15 days later than the current would minimize yield reduction in the mid- and end-century.

► In central Indian Punjab, temperature will increase by 5.1 °C in the end of 21st century. ► Model simulations predicted reduction in crop yields in future associated with shortening of growth period due to increased temperature. ► Yield reduction was more with Tmax and in fine textured soils. ► Evapotranspiration, nitrogen and water-use efficiency will decrease in future. ► Postponing current planting date of rice and wheat by 15–21 days mitigated climate change impact.