Sowing window adjustments in rice (Oryza sativa), groundnut (Arachis hypogaea) and sugarcane (Saccharum species) as an adaptation strategy to changing climate scenario: A simulation study in Tamil Nadu

Abstract

Evaluation of climate-change impacts on crop yield for the north-east agroclimatic region of Tamil Nadu, was assessed during 2014, using DSSAT4.5 model under IPCC, RCP4.5 emission trajectory. Results showed that, the yields of the major crops, viz. rice (Oryza sativa L.), groundnut (Arachis hypogaea L.) and sugarcane (Saccharum sp.), tend to decrease towards the end of 21st century. In this purview, this study was an endeavour to investigate the easiest agronomic adaptation options, i.e. sowing-date adjustment to offset the projected climate-change impacts on yield. Advancing or delaying sowing dates were found to be giving better yield under climate change scenario. Results for rice showed that, adjusting the sowing dates can have better yield rates in future. Experimental outcomes showed that rice crop sown on 1st November led to a yield increase of 2.18%, and this would be the most appropriate response to offset the impacts. The groundnut sown on 10th December and 1 January were performing well, with a yield increment of 7.51 and 7.50%, respectively, by the end of century. For sugarcane, planting season extends to 6 months in the study area. The results revealed that, planting on 15th March can increase the yield by 3.5% in the near century period under RCP 4.5. The overall agreement between simulated and observed rice yields was 74% with an R2 and (RMSE) values of 0.92 and 807 kg/ha respectively. The overall agreement between simulated and observed groundnut yield was 82% with R2 , root mean square error (RMSE) values of 0.71 and 408.98 kg/ha respectively. The agreement between simulated and observed sugarcane yields was 76% with 0.76 and 25.82 tonnes/ha as R2 and RMSE values respectively. The challenge is to disseminate this information for the benefit of the farmers as part of awareness creation, preparedness and capacity building. Therefore, researchers and agriculturists have a major role to play in taking forward, scientific findings for the benefit of the stakeholders.