The possible effects of global warming on cropping systems in China: IV. The possible impact of future climatic warming on the northern limits of spring maize in three provinces of Northeast China.

Abstract

【Objective】 The fact that temperature in China had increased significantly in the context of global climate change has become a consensus.The effects of this change on China's agricultural production,especially on cropping systems and crop distribution have attracted more and more attention of the Chinese government and scientists.【Method】 In this paper,using the accumulated temperature with different guarantee rates by empirical frequencies method,the changes of the northern limits of different maturity-types of spring maize varieties and the changes of water deficient ratio in the study region were analysed,based on the meteorology data in both A2 and B1 climatic scenarios.【Result】 The northern limits of different maturity-types of spring maize varieties moved northward with different degrees without considering the effect of elevated CO2 concentration on the growth and development of crop in future climate scenarios.In the sensitive region,the early-maturity varieties will be replaced by the middle and late maturity varieties,making the growth period longer and the dry matter increased,which can improve the yield of spring maize in three provinces of Northeast China.However,the increase of water deficient ratio will bring a certain risk of northward movement in the 21 mid-century.【Conclusion】 Heat and water resources should be comprehensively considered in the northward movement of different maturity-types of spring maize varieties.Spring maize should plant in the suitable region in order to reduce the loss of maize yield due to the draught.