Impacts of climate warming and crop management on maize phenology in northern China

Climate warming has and will continue to exert a significantly impact on crop phenology in the past and coming decades. Combining observed data of phenology and a crop growth model provides a good approach for quantitating the effects of climate warming and crop management on crop phenology. The purpose of this study is to determine the impacts of temperature change, sowing date (SD) adjustment and cultivar shift on maize phenology in northern China during 1981-2010. Results indicated that climate warming caused anthesis date (AD) and maturity date (MD) of maize to advance by 0.2-5.5 and 0.6-11.1 d/10a, respectively. Due to climate-driven changes in maize phenology, three growth periods of maize, i.e., vegetative growth period (VGP; from sowing to anthesis), reproductive growth period (RGP; from anthesis to maturity) and whole growth period (WGP; from sowing to maturity) shortened by 0.2-5.5, 0.4-5.6 and 0.6-11.1 d/10a, respectively. With SD adjustment (i.e., SD advancement), AD and MD occurred early by 0.5-2.6 and 0.1-3.4 d/10a, respectively. SD adjustment caused duration of VGP of maize to prolong. However, duration of RGP slightly shortened by 0.1-1.3 d/10a. Furthermore, due to cultivar shift, MD of maize significantly delayed by 4.9-12.2 d/10a. Durations of VGP, RGP and WGP of maize prolonged by 0.2-4.1, 1.6-8.4 and 4.3-11.8 d/10a, respectively. In conclusion, our results indicated that cultivar shift, to some extent, could mitigate the negative impact of climate warming on maize phenology.