Network Project on Impact, Adaptation and Vulnerability of Indian Agriculture to Climate Change Annual Report 2008 - 09

Abstract

Analysis on mean annual temperature trends of 47 locations spread across the country indicated increasing trend in the central and southern parts and north eastern region. While decreasing trend is observed in some parts of Gujarat, Konkan region, NW parts of Madhya Pradesh and Eastern Rajasthan. l Experiments conducted under controlled environment conditions (FACE, TGT, OTC and portable chamber) to assess the effect of elevated temperature and CO2 showed that a rise in atmospheric temperature reduced the biomass and yield of rice, greengram, pigeon pea, wheat and chickpea. Among the crops rice, pigeonpea and chickpea showed greater thermal stability as compared to greengram and wheat. Rice and chickpea showed greater thermal sensitivity during reproductive growth phase, while pigeonpea and greengram showed greater thermal sensitivity during ripening growth phase. Inreased CO2 lead to higher biomass in plantation crops such as coconut, arecanut and cocoa; while reduced stomatal conductance, stomatal density and leaf surface wax leading to increased water use efficiency. However, slight reduction in polyphenols may predispose coconut and cocoa plants for pest and disease incidence in elevated CO2 conditions. Tomato yields increased by 26.5% in elevated CO2 (550ppm). l In order to quantify the impact of climate change on quality, analysis was carried out on the economic produce of various crops. Results indicated that protein content of wheat, greengram and chickpea grain increased marginally with rise in temperature, whereas it decreased marginally with rise in CO2 level. Starch content however, showed reverse trend under elevated temperature and CO2 in wheat grain. Oil content of sunflower seed increased markedly under elevated CO2 condition. In tomato, even though lycopene and carotenoid content did not differ, antioxidants were higher at elevated CO2 (550 ppm) concentrations. Influence of storage temperature from 22 to 45o C on keeping quality of coconut copra and oil reduced oil percentage while it increased starch, carbohydrates and reducing sugars in copra. It also reduced the shelf life of coconut oil as indicated by increase in free fatty acids, acid value and peroxide value. l While crops may take some time to adapt to climate change, our preliminary results showed that high thermal stress imposed on soil microorganism led to the generation of some distinct forms indicating their rapid adaptation to further extended/widened range of temperature. l The impacts of climate change on hydrology of Belura watersheds Akola, using SWAT model indicated that under same cropping pattern and management activities, surface runoff and total sediment load, total aquifer recharge, water yield and PET are likely to increase significantly with increase in rainfall. The cost of bunding and trenching is likely to increase considerably due to additional earth work required.