Simulation of global warming effect on irrigated rice phenology in the major rice production region of Iran, Rasht

The effects of global warming on crop production and food security are of concern and have been extensively evaluated by various simulation models. The effect of future climate on rice phenology was investigated under climate change scenarios in Rasht station in this study. Data for this research includes the meteorological, soil and crop management data. Meteorological data include the daily data of minimum temperature, maximum temperature, solar radiation and precipitation during 1981–2010 and monthly temperature and precipitation of general circulation models during 1971–2000. Soil and product management data were provided from field experiment in the Iranian Rice Research Institute in Rasht, from 2008 to 2009. We used stochastic weather generators (Lars-WG) for downscaling of climate model. The prediction of climate did using of ECHAM5 model under of SRA1B, SRA2 and SRB1 scenarios. This model was validated using RMSE and MAE. Ceres-Rice model was used for simulating of rice phonology in two irrigation regimes (continuous submergence and irrigation at 5-day intervals). Results show that minimum and maximum temperature will increase in the Rasht during the rice-growing season. Simulation of rice phenology showed the beginning of Panicle Initiation, anthesis and physiological maturity day will happen earlier with increasing of temperature in continuous submergence and will not happen earlier with increase in interval of irrigation. Also, the beginning of phonological stages will delay with increasing of temperature above 1°C even in continuous submergence.