Impacts of Recent Temperatures Rise on Double-Rice Phenology Across Southern China

Abstract

Rice phenology was determined by temperature and agronomic management. It was essential to quantify the interaction between warming temperatures and rice phenology to understand the impact of climate change in rice farming systems. Based on the quantitative analysis of data from double-cropping rice in the south of China in the last 20 years, we found that the average temperature of the whole growth periods of early rice and late rice increased by an average of 0.76 °C and 0.49 °C decade−1, respectively. The whole growth period (WGP) change trend of early rice decreased by 0.07 d decade−1, but the WGP of late rice increased 1.26 d decade−1. The vegetative growth period (VGP) and the reproductive growth period (RGP) of early rice and late rice were all shorted. Regression analysis showed that the VGP of early rice and late rice decreased by 2.99 days and 2.82 days, and the RGP decreased by 1.67 days and 1.81 days, respectively, as the mean air temperature increased by 1 °C during the corresponding stages. The WGPs of early rice and late rice decreased by 3.81 days and 5.31 days, respectively, with the mean air temperature increased by 1 °C during growth duration. According to our studies, the rising mean air temperature could lead to a shortening of the double-rice growth period. Therefore, we must adjust the planting pattern of the double-rice system to mitigate and adapt to future climate change.