Abstract

Crop production is inherently sensitive to variability in climate. Temperature and CO2 are two important parameters related to climate change, affecting crop yield in a particular region. In this study, an attempt has been made to assess the impact of these two parameters on the productivity of maize crop taking sub tropical region of Jammu as study area. A CERES-Maize model 4.0 was used for this purpose. Three-year weather data (2004-06) is used to simulate the actual yield under rainfed and irrigated conditions. Yield was simulated with elevated temperature (1, 3 and 5oC) and CO2 (440, 550 and 660 ppm) during the growing season. As changes in CO2 concentration and temperature likely to occur concomitantly, so growth and development of maize plant at three temperature regimes (1, 3 and 5oC) under double (660 ppm) CO2 concentration to the baseline (330 ppm) was also assessed. The difference in yield, biomass, grain number and LAI was estimated and analyzed to assess the effect of elevated temperature and CO2. Results revealed that the rise in temperature accelerated plant phenology, reducing dry matter accumulation and crop yield by 5 to 60 per cent. Elevation of CO2 in the level of 440, 550 and 660 ppm showed gradual yield increment of 2.01, 3.92 and 5.37 per cent under rainfed conditions and 2.33, 4.52 and 7.41 per cent under irrigated conditions, respectively. Doubled CO2 increased yield at all the temperature rise situation and completely mitigated the yield and biomass reduction due to temperature rise up to 1oC.