Adaption of rice–wheat cropping system to climate warming in Jianghuai area

: As the climate warming is increasing, the global average surface temperature has risen by nearly 1°C in the past 100 years. Rice-wheat cropping system is the mainstream cropping system in the lower reaches of the Yangtze River and Huaihe River in Jiangsu and Anhui provinces, but its adaptation to climate warming is still unclear. We analyzed the characteristics of temperature rise and crop phenological changes in the rice–wheat double cropping area of Jiangsu using the historical data from 34 meteorological stations and 45 phenological stations over the years. The results revealed that the range of temperature increase in Jianghuai area was higher in the south than in the north, higher in wheat season and lower in rice ripe season, and the highest in March. In the rice season, the sowing date in Jiangnan was delayed by 3.4 d 10a –1 , the heading date in Huainan was advanced by 2 d 10a –1 , and the harvest date in Huaibei was delayed by 6.2 d 10a –1 . In the wheat season, the sowing date in Jiangnan was delayed by 6.4 d 10a –1 , and the heading and harvest time tended to be earlier in the whole region. The rice–wheat stubble stage was shortened by 4.6 d 10a –1 in Huaibei and 6.9 d 10a –1 in Jiangnan. The average temperature of rice and wheat during growth period had no significant change, but in wheat season increased by 0.008–0.346 kg hm –2 °C –1 10a –1 . Warming decreased wheat yields in the north of Yangtze River and Huainan area, but increased wheat yield in Huaibei area. In summary, these results indicated that the rice-wheat cropping system in Jianghuai was gradually adapting to the climate warming, and the negative effects of climate warming on crop yield could be alleviated by reasonably changing sowing date. Our findings can provide reference for climate change adaptation cultivation and cultivation technology innovation.