Hindcasting the effects of climate change on rice yields, irrigation requirements, and water productivity

An ex post facto investigation of the effects of climate change on rice production over the past few decades will be helpful for planning future climate change. Here, a simulation study was carried out to evaluate the impacts of climate change on the yields, irrigation requirements, and water productivity of rice in Kaifeng, China from 1951 to 2010. The rice growth model ORYZA 2000 was adopted to simulate the yields and irrigation requirements (IR); then, water productivity in terms of irrigation water (WPI), evapotranspiration (WPET), and total water use (WPI+R) was calculated, and the Mann–Kendall test was employed to detect the trends in the variables. The reduction in yield was caused by the shortened GSL, increased temperature, and decreased hours of sunshine. The decreased seasonal IR resulted from both the increased rainfall and decreased ETc, while the latter played a dominate role. The WPI seemed not sensitivity to climate change, while WPET and WPI+R were strongly linked with climate change. More productive crop variety or changing the planting schedule could avoid the negative effects posed by global warming, stilling, and dimming.