Impacts of climate change on winter wheat and summer maize dual-cropping system in the North China Plain

Climate change exacerbates the frequency of agricultural-relevant climate extremes, which could threaten crop growth and food production. The North China Plain (NCP), as one of the most important food production bases in China, is dominated by winter wheat and summer maize. The response of this dual-cropping system to climate change has not been thoroughly evaluated. In this study, the remote sensing normalized difference vegetation index (NDVI) was used to extract the dynamic phenology of winter wheat and summer maize and characterize crop growth status. The meteorological data from 1982 to 2015 were used to examine the mean climate factors and four typical climate extremes (including heat stress, spring frost, meteorological drought, and extreme wet events) associated with phenology shifts. Then, the effects of climate changes on winter wheat and summer maize growth were explored by a panel regression model. In the NCP during 1982-2015, the winter wheat growth exhibited no significant sensitivity to the four climate extremes, and only extreme wet event exerted a significant impact on summer maize growth. The insensitivity of crop growth to climate extremes may benefit from widespread irrigation, improved cultivars and agricultural management (e.g., topdressing and insect pests control). In addition, over the last 34 years, mean climate conditions, especially average temperature, solar radiation and vapor pressure deficit, generally made more contributions to the variations of wheat and maize growth than climate extremes, indicating that mean climate conditions dominated crop growth changes in the NCP. Our findings highlight the possible effects of climate change on crop growth of regional dual-cropping system and provide a critical foundation for future effective measures to ensure regional food production.