Exploring options to grow rice using less water in northern China using a modelling approach: I. Field experiments and model evaluation

Chinaʹs grain basket in the North China Plain is threatened by increasing water scarcity and there is an urgent need to develop water-saving irrigation strategies. Water savings in rice can be realized by alternate wetting and drying (AWD) under lowland conditions, or by aerobic rice in which the crop is grown under nonflooded conditions with supplemental irrigation. Field experimentation and simulation modelling are a powerful combination to understand complex crop-water interactions and to extrapolate site-specific empirical results to other environments and conditions. In this paper, we present results from 4 years of field experiments on AWD and aerobic rice in 2001–2004 near Kaifeng, Henan Province, China. The experimental data were used to parameterize and evaluate the rice growth model ORYZA2000. A subsequent paper reports on the extrapolation of the experimental results using ORYZA2000 and on farmer-participatory testing of aerobic rice.