Crop simulation mediated assessment of climate change impact on rice grown under temperate high-altitude valley of Kashmir

Abstract

The major parameters that affect climate change pattern include the latitude, ocean currents, wind, air pressure, elevation and relief. These parameters can influence the behaviour of the crops and their performance in time and space. The study was carried out to gain the perspicacity about the prospectus of cultivation of ruling japonica rice variety, K-332, under climate change scenario for the next few decades across temperate high-altitude ecology (2000–2300 msl) of Kashmir valley located within the Northwestern Himalayas. Grown over a long period of time, K-332 was released in the year 1972 and is still popular among the farmers. The variety has supported the food security in rice-growing hilly and mountainous areas of the region spread across 50,000 ha area. A study was carried out with effect from the year 2000 up till 2019 for 20 years in order to understand the phenology and stability of yield performance of the variety under changing climate scenario using DSSAT CERES crop simulation model (v.4.7). Model simulated traits, namely, days to anthesis, days to physiological maturity, tiller number and grain yield, marked an agreement with the observed data with low mean absolute error, high R2 (0.85–0.94), high modified index of agreement (0.74–0.85) and modified modelling efficiency varying from 0.47 for the traits. Eighteen CMIP5 model ensemble output projections along with the best performing individual climatic model (CCSM4) temperature projections for India and 24 CMIP5 model downscaled temperature projections for mountainous Jammu and Kashmir were used to study the impact of increased temperature on phenology and yield of K-332 as compared to nine other varieties. Days to anthesis and days to physiological maturity of all the 10 studied rice varieties were simulated to decrease, but the grain yield of high-altitude varieties was predicted to increase with the increase in temperature under all the future temperature projections. High-altitude varieties will have higher increase in grain yield as compared to low-altitude varieties under different RCPs, with maximum increase in their yield expected under RCP 8.5 (18 CMIP5 model ensemble output) over 2070–2099. Grain yield of low-altitude varieties will increase progressively up to projected temperature increase up to 3 °C and will decrease thereafter. Among the different varieties, the grain yield of K-332 will have a maximum increase (8.70%) by 2070–2099 under RCP 8.5 (18 CMIP5 model ensemble output). The study revealed the scope of rice cultivation with the same variety in high altitudes with a potential to not only sustain the climate change effect but exploit it for better yield performance due to the moderation of low temperature stress and the reversing of the limitations thus far posed by sub-optimal temperatures and short growing period.