Effects of climate change and crop management on changes in rice phenology in China from 1981 to 2010.

Background Crop phenology change is co-determined by climate change and adaptation strategies, such as crop management, but their combined and isolated impacts on rice phenology are still unclear. Quantifying the impacts and identifying the main contributors are critical to food security under climate change. Thus we distinguished and quantified the relative contribution of climate change and crop management to rice (Oryza sativa L.) phenological changes in China from 1981 to 2010, using a first-difference multivariate regression method. Results Rice phenology has changed over the past 30 years in China. The mean length of the phenological stage from emergence to transplanting was shortened, whereas the mean length of the stage from transplanting to heading, from heading to maturity, was prolonged. The relative contribution of crop management was greater than that of climate change for single and late rice, which took up over 90% of the total change in certain phenology stages. Among the climatic factors, temperature was the dominant contributor, which accounted for more than 50% of the change in rice phenology. The stage from transplanting to heading of early rice and late rice had strongly negative sensitivities to increasing temperature. Conclusions Crop management has offset the adverse effects of climate change on single and early rice phenology in China over the past 30 years to some extent, while further adaptation measures such as adjusting sowing date, shifting rice varieties, applying nitrogen fertilizer and irrigation should be applied to late rice in southern China, especially in a warmer future. © 2021 Society of Chemical Industry.