The Suitability of the Emerging Double Maize System Towards Sustainable Water Use under a Warm Temperature Continental Monsoon Climate

Double cropped winter wheat and summer maize system is a system that can improve food security, however, overexploitation of groundwater for irrigation limits its use. An alternative to the wheat/maize system is double cropped maize system. The objective of this study was to evaluate whether a new double maize system could improve yield with a sustainable water use manner. Higher temperature has provided an opportunity to develop an alternative double maize system across the North China Plain (NCP) using the Hybrid-Maize model. Six combinations of long-season and short-season (LS and SS, respectively) maize varieties and two plastic film mulching treatments were used to evaluate the regional suitability of the new system. The average yield potential of the double maize system ranged from 19.6 to 21.3 Mg ha(-1), comparable to the conventional winter wheat-summer maize system (Con W/M). The combination of SS and SS varieties using plastic film mulching (SS-SS[P]) has applicability to the environments with growing degree-days (GDD) at similar to 2566 degrees C worldwide with a yield potential of 20.2 Mg ha(-1). Although the similar yield potential can also be achieved for the combinations of SS-LS (P) and LS-SS (P), the frost risk of the two combinations for the second season maize was more than 80%. These results indicated that changing from a Con W/M to the newly-developed double cropped maize system could result in major improvements in both crop production and water usage under current and future climate scenarios.