Effect of Irrigation Method on Adaptation Capacity of Rice to Climate Change in Subtropical India

Abstract

Water management technologies under projected climate change will play key role in sustainable rice production. Modeling approach was used to assess the impact of climate change on rice production under drip irrigation (DIR) and conventional puddle transplanted (PTR) in subtropical India. The genotype coefficients of CERES-Rice model (cv. Naveen) were determined and tested using experimental data for the years 2012–2014. Close match between the observed and simulated values was recorded during both the years which led to higher d-index (> 0.95) and lower normalized RMSE (RMSEn) values. Under the projected climate change scenarios (RCP 4.5 and RCP 8.5), grain yield reduced over the period 2020–2080, with higher decline in RCP 8.5. Over the period, higher nitrogen (N) use efficiency in DIR led to lower yield reduction over PTR. Among the different adaptation measures, higher fertilizer N dose was able to mitigate negative impact of temperature rise up to 3.3 °C over base period, beyond which grain yield was significantly reduced. Results of the simulations for the different sowing dates stated higher reduction in grain yield with delayed sowing in DIR as well as in PTR for both (RCP 4.5 and 8.5) climate change scenarios. However, early sowing resulted in better crop establishment in DIR leading to better yield compared to PTR in both the climate change scenarios.