Model-based approach to quantify production potentials of summer maize and spring maize in the north China plain
The North China Plain (NCP) belongs to the major maize (Zea mays L.) growing areas in China. Maize yields have increased steadily since the 1980s, but in recent years average yields have stabilized around 5000 kg ha–1. The objective of this study was to quantify the production potential of summer and spring maize in the NCP. For this purpose the CERES-Maize model was calibrated and validated. The variability caused by climate was considered by using up to 30 yr of weather data from 14 meteorological stations across the NCP. Simulations were carried out for five different soil texture. Results were linked to a Geographic Information System (GIS). The results of the model calibration and validation showed a good fit between simulated and measured yield. Average simulated grain yield for summer maize was 4800 kg ha–1 and for spring maize was 5700 kg ha–1. Yields of summer maize were limited by the duration of the growing period. In order to increase spring maize yields, two strategies were developed. The first approach was to sow spring maize at a time when water deficit was least likely to occur during the late vegetative, flowering, and grain-filling stages. A delay in sowing of 30 d shifted maize development closer to the rainy season and increased average yield by 13%. In a second test the use of a variety with a later flowering date as a result of a longer vegetative growth led to an average increase in yield of 15%.