Impacts of temperature on rice yields of different rice cultivation systems in southern China over the past 40 years

• Higher Tmax had obviously negative impact on middle rice yield during past 40 years.
• Increase of Tmax had weak impact on early rice and late rice yield.
• Increase of Tmin had significant negative impact on middle rice and early rice yields.
• Increase of Tmin had significant positive impact on the late rice yield.

The impact of climate change on rice yield in China remains highly uncertain. We examined the impact of the change of maximum temperature (Tmax) and minimum temperature (Tmin) on rice yields in southern China from 1967 to 2007. The rice yields were simulated by using the DSSAT3.5 (Decision Support System for Agro-technology Transfer)-Rice model. The change of Tmax and Tmin in rice growing seasons and simulated rice yields as well as their correlations were analyzed. The simulated yields of middle rice and early rice had a decreasing trend, but late rice yields showed a weak rise trend. There was significant negative correlation between Tmax and the early rice yields, as well as the late rice yields in most stations, but non-significant negative correlation for the middle rice yields. An obviously negative relationship was found between Tmin and the early and middle rice yields, and a significant positive relationship was found between Tmin and the late rice yields. It indicated that under the recent climate warming, the increased Tmax brought strong negative impacts on early rice yields and late rice yields, but a weak negative impact on the middle rice yields; the increased Tmin had a strong negative impact on the middle rice yields and the early rice yields, but a significant positive impact on the late rice yields. It suggested that it is necessary to adjust rice planting date and adapt to higher Tmin.